diff --git a/collects/plot/common/area.rkt b/collects/plot/common/area.rkt
index a79fc2828f..615d754ce3 100644
--- a/collects/plot/common/area.rkt
+++ b/collects/plot/common/area.rkt
@@ -15,7 +15,8 @@
          "draw.rkt"
          "math.rkt"
          "sample.rkt"
-         "parameters.rkt")
+         "parameters.rkt"
+         "legend.rkt")
 
 (provide plot-area%)
 
@@ -346,16 +347,16 @@
         (match-define (vector x y) v)
         
         (when outline?
-          (define alpha (send dc get-alpha))
+          ;(define alpha (send dc get-alpha))
           (define fg (send dc get-text-foreground))
           
-          (send dc set-alpha (alpha-expt alpha 1/8))
+          ;(send dc set-alpha (alpha-expt alpha 1/2))
           (send dc set-text-foreground (send dc get-background))
           (for* ([dx  (list -1 0 1)]
                  [dy  (list -1 0 1)]
                  #:when (not (and (zero? dx) (zero? dy))))
             (draw-text/anchor dc str (+ x dx) (+ y dy) anchor #t 0 angle))
-          (send dc set-alpha alpha)
+          ;(send dc set-alpha alpha)
           (send dc set-text-foreground fg))
         
         (draw-text/anchor dc str x y anchor #t 0 angle)))
@@ -607,9 +608,3 @@
       
       (clear-clipping-rect))
     ))  ; end class
-
-(struct legend-entry (label draw) #:transparent)
-
-(provide (contract-out
-          (struct legend-entry ([label string?] [draw ((is-a?/c plot-area%) real? real? real? real?
-                                                                            . -> . void?)]))))
diff --git a/collects/plot/common/axis-transform.rkt b/collects/plot/common/axis-transform.rkt
index 1102f999ba..a0df27155a 100644
--- a/collects/plot/common/axis-transform.rkt
+++ b/collects/plot/common/axis-transform.rkt
@@ -5,48 +5,35 @@
          "contract.rkt"
          "contract-doc.rkt")
 
-(provide id-function
-         axis-transform/c
-         id-transform
-         apply-transform
-         make-axis-transform
-         axis-transform-compose
-         axis-transform-append
-         axis-transform-bound
-         log-transform
-         cbrt-transform
-         hand-drawn-transform
-         stretch-transform
-         collapse-transform)
+(provide (all-defined-out))
 
 (struct invertible-function (f g) #:transparent)
 
-(provide (contract-out (struct invertible-function ([f (real? . -> . real?)]
-                                                    [g (real? . -> . real?)]))))
-
-(define (invertible-compose f1 f2)
+(defproc (invertible-compose [f1 invertible-function?] [f2 invertible-function?]
+                             ) invertible-function?
   (match-let ([(invertible-function f1 g1)  f1]
               [(invertible-function f2 g2)  f2])
     (invertible-function (compose f1 f2) (compose g2 g1))))
 
-(define axis-transform/c (real? real? invertible-function? . -> . invertible-function?))
+(defcontract axis-transform/c (real? real? invertible-function? . -> . invertible-function?))
 
 (defproc (id-transform [x-min real?] [x-max real?] [old-function invertible-function?]
                        ) invertible-function?
   old-function)
 
-(define id-function (invertible-function (λ (x) x) (λ (x) x)))
+(defthing id-function invertible-function? (invertible-function (λ (x) x) (λ (x) x)))
 
 (defproc (apply-transform [t axis-transform/c] [x-min real?] [x-max real?]) invertible-function?
   (t x-min x-max id-function))
 
 ;; Turns any total, surjective, monotone flonum op and its inverse into an axis transform
-(define ((make-axis-transform f g) x-min x-max old-function)
-  (define fx-min (f x-min))
-  (define fx-scale (/ (- x-max x-min) (- (f x-max) fx-min)))
-  (define (new-f x) (+ x-min (* (- (f x) fx-min) fx-scale)))
-  (define (new-g y) (g (+ fx-min (/ (- y x-min) fx-scale))))
-  (invertible-compose (invertible-function new-f new-g) old-function))
+(defproc (make-axis-transform [f axis-transform/c] [g axis-transform/c]) axis-transform/c
+  (λ (x-min x-max old-function)
+    (define fx-min (f x-min))
+    (define fx-scale (/ (- x-max x-min) (- (f x-max) fx-min)))
+    (define (new-f x) (+ x-min (* (- (f x) fx-min) fx-scale)))
+    (define (new-g y) (g (+ fx-min (/ (- y x-min) fx-scale))))
+    (invertible-compose (invertible-function new-f new-g) old-function)))
 
 ;; ===================================================================================================
 ;; Axis transform combinators
diff --git a/collects/plot/common/contract-doc-stx.rkt b/collects/plot/common/contract-doc-stx.rkt
deleted file mode 100644
index f61171f12c..0000000000
--- a/collects/plot/common/contract-doc-stx.rkt
+++ /dev/null
@@ -1,15 +0,0 @@
-#lang racket/base
-
-(require syntax/parse)
-
-(provide (all-defined-out))
-
-(struct proc+doc (proc-transformer doc-transformer)
-    #:property prop:procedure (λ (p stx) ((proc+doc-proc-transformer p) stx)))
-  
-(define-syntax-class argument-spec
-  #:description "argument specification"
-  (pattern [name:id contract:expr])
-  (pattern [name:id contract:expr default:expr])
-  (pattern [kw:keyword name:id contract:expr])
-  (pattern [kw:keyword name:id contract:expr default:expr]))
\ No newline at end of file
diff --git a/collects/plot/common/contract-doc.rkt b/collects/plot/common/contract-doc.rkt
index 8156023e9e..21d4b4d5ea 100644
--- a/collects/plot/common/contract-doc.rkt
+++ b/collects/plot/common/contract-doc.rkt
@@ -2,33 +2,23 @@
 
 ;; Definitions with contracts and contract documentation.
 
-(require racket/contract
-         (for-syntax racket/base racket/list syntax/parse
-                     "serialize-syntax.rkt"
-                     "contract-doc-stx.rkt")
+(require racket/contract unstable/latent-contract racket/provide
+         (for-syntax racket/base racket/list racket/syntax syntax/parse racket/provide-transform
+                     "serialize-syntax.rkt")
          (prefix-in s. scribble/manual)
          (prefix-in s. scribble/core)
          (prefix-in s. scribble/html-properties))
 
-(provide defproc defparam defthing defcontract doc-apply)
-
-(define-for-syntax (make-proc+doc id-stx doc-transformer)
-  (proc+doc
-   (λ (stx)
-     (syntax-case stx ()
-       [(_ . args)  (quasisyntax/loc stx (#,id-stx . args))]
-       [_           (quasisyntax/loc stx #,id-stx)]))
-   doc-transformer))
-
-;; Applies the documentation transformer (use within a scribble/manual module)
-(define-syntax (doc-apply stx)
-  (define (error) (raise-syntax-error 'doc-apply "no associated doc transformer" stx))
-  (syntax-parse stx
-    [(_ name:id . pre-flows)
-     (define p (syntax-local-value #'name error))
-     (when (not (proc+doc? p)) (error))
-     ((proc+doc-doc-transformer p) (syntax/loc stx (name . pre-flows)))]))
+(provide defthing defproc defparam defcontract
+         only-doc-out doc-apply)
 
+(begin-for-syntax
+  (define-syntax-class argument-spec
+  #:description "argument specification"
+  (pattern [name:id contract:expr])
+  (pattern [name:id contract:expr default:expr])
+  (pattern [kw:keyword name:id contract:expr])
+  (pattern [kw:keyword name:id contract:expr default:expr])))
 
 ;; A define-with-value form for scribble documentation
 (define (def/value def val . pre-flows)
@@ -73,21 +63,76 @@
           [else  (substring name-str 0 1)]))
   (datum->syntax name-stx (string->symbol arg-name-str)))
 
-(define-for-syntax (make-value-name id-stx)
-  (datum->syntax #f (syntax->datum id-stx)))
-
-(define-for-syntax (make-doc-name ctx id-stx)
-  (datum->syntax ctx (syntax->datum id-stx)))
-
 ;; ===================================================================================================
-;; define-with-contract+doc forms
+;; Forms to define things with a contract and documentation
+
+;; Define a thing, optionally documenting the value of the thing
+(define-syntax (defthing stx)
+  (syntax-parse stx
+    [(_ name:id contract:expr #:document-value value:expr)
+     (with-syntax ([name:doc             (format-id #'name "~a:doc" #'name)]
+                   [serialized-contract  (serialize-syntax #'contract)]
+                   [serialized-value     (serialize-syntax #'value)])
+       (syntax/loc stx
+         (begin
+           (define/latent-contract name contract value)
+           (define-syntax (name:doc doc-stx)
+             (syntax-case doc-stx ()
+               [(ctx . pre-flows)
+                (with-syntax ([doc-name      (datum->syntax #'ctx (syntax-e #'name))]
+                              [doc-contract  (unserialize-syntax #'ctx 'serialized-contract)]
+                              [doc-value     (unserialize-syntax #'ctx 'serialized-value)])
+                  (syntax/loc doc-stx
+                    (def/value
+                      (s.defthing doc-name doc-contract)
+                      (s.racketblock doc-value)
+                      . pre-flows)))])))))]
+    [(_ name:id contract:expr value:expr)
+     (with-syntax ([name:doc             (format-id #'name "~a:doc" #'name)]
+                   [serialized-contract  (serialize-syntax #'contract)])
+       (syntax/loc stx
+         (begin
+           (define/latent-contract name contract value)
+           (define-syntax (name:doc doc-stx)
+             (syntax-case doc-stx ()
+               [(ctx . pre-flows)
+                (with-syntax ([doc-name      (datum->syntax #'ctx (syntax-e #'name))]
+                              [doc-contract  (unserialize-syntax #'ctx 'serialized-contract)])
+                  (syntax/loc doc-stx
+                    (s.defthing doc-name doc-contract . pre-flows)))])))))]))
 
 ;; Define a procedure
 (define-syntax (defproc stx)
   (syntax-parse stx
+    [(_ (name:id arg:argument-spec ...) result:expr #:document-body body ...+)
+     (define arg-list (syntax->list #'(arg ...)))
+     (with-syntax ([name:doc            (format-id #'name "~a:doc" #'name)]
+                   [(new-arg ...)       (append* (map remove-contract arg-list))]
+                   [(req-contract ...)  (append* (map get-required-contract arg-list))]
+                   [(opt-contract ...)  (append* (map get-optional-contract arg-list))]
+                   [serialized-args     (serialize-syntax #'(arg ...))]
+                   [serialized-result   (serialize-syntax #'result)]
+                   [serialized-body     (serialize-syntax #'(body ...))])
+       (syntax/loc stx
+         (begin
+           (define/latent-contract (name new-arg ...) (->* (req-contract ...) (opt-contract ...)
+                                                           result)
+             body ...)
+           (define-syntax (name:doc doc-stx)
+             (syntax-case doc-stx ()
+               [(ctx . pre-flows)
+                (with-syntax ([doc-name    (datum->syntax #'ctx (syntax-e #'name))]
+                              [doc-args    (unserialize-syntax #'ctx 'serialized-args)]
+                              [doc-result  (unserialize-syntax #'ctx 'serialized-result)]
+                              [doc-body    (unserialize-syntax #'ctx 'serialized-body)])
+                  (syntax/loc doc-stx
+                    (def/value
+                      (s.defproc (doc-name . doc-args) doc-result)
+                      (s.racketblock . doc-body)
+                      . pre-flows)))])))))]
     [(_ (name:id arg:argument-spec ...) result:expr body ...+)
      (define arg-list (syntax->list #'(arg ...)))
-     (with-syntax ([value-name          (make-value-name #'name)]
+     (with-syntax ([name:doc            (format-id #'name "~a:doc" #'name)]
                    [(new-arg ...)       (append* (map remove-contract arg-list))]
                    [(req-contract ...)  (append* (map get-required-contract arg-list))]
                    [(opt-contract ...)  (append* (map get-optional-contract arg-list))]
@@ -95,112 +140,68 @@
                    [serialized-result   (serialize-syntax #'result)])
        (syntax/loc stx
          (begin
-           (define/contract (value-name new-arg ...) (->* (req-contract ...) (opt-contract ...)
-                                                             result)
+           (define/latent-contract (name new-arg ...) (->* (req-contract ...) (opt-contract ...)
+                                                           result)
              body ...)
-           (define-syntax name
-             (make-proc+doc
-              #'value-name
-              (λ (doc-stx)
-                (syntax-case doc-stx ()
-                  [(ctx . pre-flows)
-                   (with-syntax ([doc-name    (make-doc-name #'ctx #'name)]
-                                 [doc-args    (unserialize-syntax #'ctx 'serialized-args)]
-                                 [doc-result  (unserialize-syntax #'ctx 'serialized-result)])
-                     #'(s.defproc (doc-name . doc-args) doc-result . pre-flows))])))))))]))
+           (define-syntax (name:doc doc-stx)
+             (syntax-case doc-stx ()
+               [(ctx . pre-flows)
+                (with-syntax ([doc-name    (datum->syntax #'ctx (syntax-e #'name))]
+                              [doc-args    (unserialize-syntax #'ctx 'serialized-args)]
+                              [doc-result  (unserialize-syntax #'ctx 'serialized-result)])
+                  (syntax/loc doc-stx
+                    (s.defproc (doc-name . doc-args) doc-result . pre-flows)))])))))]))
 
 ;; Define a parameter
 (define-syntax (defparam stx)
   (syntax-parse stx
     [(_ name:id arg:id contract:expr default:expr)
-     (with-syntax ([value-name           (make-value-name #'name)]
+     (with-syntax ([name:doc             (format-id #'name "~a:doc" #'name)]
                    [serialized-contract  (serialize-syntax #'contract)]
                    [serialized-default   (serialize-syntax #'default)])
        (syntax/loc stx
          (begin
-           (define/contract value-name (parameter/c contract) (make-parameter default))
-           (define-syntax name
-             (make-proc+doc
-              #'value-name
-              (λ (doc-stx)
-                (syntax-case doc-stx ()
-                  [(ctx . pre-flows)
-                   (with-syntax ([doc-name      (make-doc-name #'ctx #'name)]
-                                 [doc-arg       (make-doc-name #'ctx #'arg)]
-                                 [doc-contract  (unserialize-syntax #'ctx 'serialized-contract)]
-                                 [doc-default   (unserialize-syntax #'ctx 'serialized-default)])
-                     #'(def/value
-                         (s.defparam doc-name doc-arg doc-contract)
-                         (s.racketblock doc-default)
-                         . pre-flows))])))))))]
+           (define/latent-contract name (parameter/c contract) (make-parameter default))
+           (define-syntax (name:doc doc-stx)
+             (syntax-case doc-stx ()
+               [(ctx . pre-flows)
+                (with-syntax ([doc-name      (datum->syntax #'ctx (syntax-e #'name))]
+                              [doc-arg       (datum->syntax #'ctx (syntax-e #'arg))]
+                              [doc-contract  (unserialize-syntax #'ctx 'serialized-contract)]
+                              [doc-default   (unserialize-syntax #'ctx 'serialized-default)])
+                  #'(def/value
+                      (s.defparam doc-name doc-arg doc-contract)
+                      (s.racketblock doc-default)
+                      . pre-flows))])))))]
     [(_ name:id contract:expr default:expr)
      (quasisyntax/loc stx
        (defparam name #,(parameter-name->arg-name #'name) contract default))]))
 
-(define-syntax (defthing stx)
-  (syntax-parse stx
-    [(_ name:id contract:expr value:expr)
-     (with-syntax ([value-name           (make-value-name #'name)]
-                   [serialized-contract  (serialize-syntax #'contract)])
-       (syntax/loc stx
-         (begin
-           (define/contract value-name contract value)
-           (define-syntax name
-             (make-proc+doc
-              #'value-name
-              (λ (doc-stx)
-                (syntax-case doc-stx ()
-                  [(ctx . pre-flows)
-                   (with-syntax ([doc-name      (make-doc-name #'ctx #'name)]
-                                 [doc-contract  (unserialize-syntax #'ctx 'serialized-contract)])
-                     #'(s.defthing doc-name doc-contract . pre-flows))])))))))]))
-
 ;; Define a contract or a procedure that returns a contract
 (define-syntax (defcontract stx)
   (syntax-parse stx
     [(_ name:id value:expr)
-     (with-syntax ([value-name        (make-value-name #'name)]
-                   [serialized-value  (serialize-syntax #'value)])
-       (syntax/loc stx
-         (begin
-           (define value-name value)
-           (define-syntax name
-             (make-proc+doc
-              #'value-name
-              (λ (doc-stx)
-                (syntax-case doc-stx ()
-                  [(ctx . pre-flows)
-                   (with-syntax ([doc-name       (make-doc-name #'ctx #'name)]
-                                 [doc-contract?  (make-doc-name #'ctx #'contract?)]
-                                 [doc-value      (unserialize-syntax #'ctx 'serialized-value)])
-                     #'(def/value
-                         (s.defthing doc-name doc-contract?)
-                         (s.racketblock doc-value)
-                         . pre-flows))])))))))]
+     (syntax/loc stx (defthing name contract? #:document-value value))]
     [(_ (name:id arg:argument-spec ...) body)
-     (define arg-list (syntax->list #'(arg ...)))
-     (with-syntax ([value-name          (make-value-name #'name)]
-                   [(new-arg ...)       (append* (map remove-contract arg-list))]
-                   [(req-contract ...)  (append* (map get-required-contract arg-list))]
-                   [(opt-contract ...)  (append* (map get-optional-contract arg-list))]
-                   [serialized-args     (serialize-syntax #'(arg ...))]
-                   [serialized-body     (serialize-syntax #'body)])
-       (syntax/loc stx
-         (begin
-           (define/contract (value-name new-arg ...) (->* (req-contract ...) (opt-contract ...)
-                                                             contract?)
-             body)
-           (define-syntax name
-             (make-proc+doc
-              #'value-name
-              (λ (doc-stx)
-                (syntax-case doc-stx (doc)
-                  [(ctx . pre-flows)
-                   (with-syntax ([doc-name       (make-doc-name #'ctx #'name)]
-                                 [doc-contract?  (make-doc-name #'ctx #'contract?)]
-                                 [doc-args       (unserialize-syntax #'ctx 'serialized-args)]
-                                 [doc-body       (unserialize-syntax #'ctx 'serialized-body)])
-                     #'(def/value
-                         (s.defproc (doc-name . doc-args) doc-contract?)
-                         (s.racketblock doc-body)
-                         . pre-flows))])))))))]))
+     (syntax/loc stx (defproc (name arg ...) contract? #:document-body body))]))
+
+;; ===================================================================================================
+;; Getting documentation
+
+(define-syntax only-doc-out
+  (make-provide-pre-transformer
+   (λ (stx modes)
+     (syntax-case stx ()
+       [(_ provide-spec)
+        (pre-expand-export
+         (syntax/loc stx
+           (matching-identifiers-out #rx".*:doc$" provide-spec))
+         modes)]))))
+
+;; Applies the documentation transformer (use within a scribble/manual module)
+(define-syntax (doc-apply stx)
+  (syntax-parse stx
+    [(_ name:id . pre-flows)
+     (with-syntax ([name:doc  (format-id #'name "~a:doc" #'name)])
+       (syntax-protect
+        (syntax/loc stx (name:doc . pre-flows))))]))
diff --git a/collects/plot/common/contract.rkt b/collects/plot/common/contract.rkt
index 6126433795..bed2f1bf7e 100644
--- a/collects/plot/common/contract.rkt
+++ b/collects/plot/common/contract.rkt
@@ -1,9 +1,10 @@
 #lang racket/base
 
-(require racket/contract racket/draw racket/class
+(require racket/contract racket/draw racket/class unstable/latent-contract
          "contract-doc.rkt")
 
-(provide (all-defined-out))
+(provide (except-out (all-defined-out) treeof)
+         (activate-contract-out treeof))
 
 ;; ===================================================================================================
 ;; Convenience
@@ -36,7 +37,7 @@
 (defcontract font-family/c (one-of/c 'default 'decorative 'roman 'script 'swiss
                                      'modern 'symbol 'system))
 
-(define known-point-symbols
+(defthing known-point-symbols (listof symbol?) #:document-value
   '(dot point pixel
         plus times asterisk 5asterisk
         odot oplus otimes oasterisk o5asterisk
diff --git a/collects/plot/common/date-time.rkt b/collects/plot/common/date-time.rkt
index 51030bb364..a06f40273f 100644
--- a/collects/plot/common/date-time.rkt
+++ b/collects/plot/common/date-time.rkt
@@ -8,16 +8,7 @@
          "math.rkt"
          "format.rkt")
 
-(provide seconds-per-minute
-         seconds-per-hour
-         seconds-per-day
-         seconds-per-week
-         avg-seconds-per-year
-         avg-seconds-per-month
-         utc-seconds-round-month
-         utc-seconds-round-year
-         plot-date-formatter
-         plot-time-formatter)
+(provide (all-defined-out))
 
 (define seconds-per-minute 60)
 (define seconds-per-hour (* 60 seconds-per-minute))
@@ -78,12 +69,7 @@
 
 (struct plot-time (second minute hour day) #:transparent)
 
-(provide (contract-out (struct plot-time ([second (and/c (>=/c 0) (</c 60))]
-                                          [minute (integer-in 0 59)]
-                                          [hour (integer-in 0 23)]
-                                          [day exact-integer?]))))
-
-(define (seconds->plot-time s)
+(defproc (seconds->plot-time [s real?]) plot-time?
   (let* ([s  (inexact->exact s)]
          [day  (floor (/ s seconds-per-day))]
          [s  (- s (* day seconds-per-day))]
@@ -93,7 +79,7 @@
          [s  (- s (* minute seconds-per-minute))])
     (plot-time s minute hour day)))
 
-(define (plot-time->seconds t)
+(defproc (plot-time->seconds [t plot-time?]) real?
   (match-define (plot-time second minute hour day) t)
   (+ second
      (* minute seconds-per-minute)
diff --git a/collects/plot/common/draw.rkt b/collects/plot/common/draw.rkt
index 8540adcb24..d2e4e2b590 100644
--- a/collects/plot/common/draw.rkt
+++ b/collects/plot/common/draw.rkt
@@ -58,7 +58,7 @@
 
 (define (color%? c) (is-a? c color%))
 
-(define (->color c)
+(defproc (->color [c color/c]) (list/c real? real? real?)
   (match c
     [(? color%?)  (list (send c red) (send c green) (send c blue))]
     [(? string?)  (define color (send the-color-database find-color c))
@@ -82,7 +82,7 @@
      (160 32 240)     ; magenta
      (160 160 160)))  ; gray
 
-(define (->pen-color c)
+(defproc (->pen-color [c plot-color/c]) (list/c real? real? real?)
   (cond [(exact-integer? c)  (vector-ref pen-colors (remainder (abs c) 8))]
         [else                (->color c)]))
 
@@ -96,11 +96,11 @@
      (240 224 255)    ; magenta
      (212 212 212)))  ; gray
 
-(define (->brush-color c)
+(defproc (->brush-color [c plot-color/c]) (list/c real? real? real?)
   (cond [(exact-integer? c)  (vector-ref brush-colors (remainder (abs c) 8))]
         [else                (->color c)]))
 
-(define (->pen-style s)
+(defproc (->pen-style [s plot-pen-style/c]) symbol?
   (cond [(exact-integer? s)  (case (remainder (abs s) 5)
                                [(0)  'solid]
                                [(1)  'dot]
@@ -110,7 +110,7 @@
         [(symbol? s)  s]
         [else  (raise-type-error '->pen-style "symbol or integer" s)]))
 
-(define (->brush-style s)
+(defproc (->brush-style [s plot-brush-style/c]) symbol?
   (cond [(exact-integer? s)  (case (remainder (abs s) 7)
                                [(0)  'solid]
                                [(1)  'bdiagonal-hatch]
@@ -146,9 +146,10 @@
     (map list rs gs bs)))
 
 ;; Returns an alpha value b such that, if 
-(define (alpha-expt a n)
+(defproc (alpha-expt [a (real-in 0 1)] [n (>/c 0)]) real?
   (- 1 (expt (- 1 a) n)))
 
-(define (maybe-apply/list list-or-proc xs)
+(defproc (maybe-apply/list [list-or-proc (or/c (listof any/c) (any/c . -> . any/c))]
+                           [xs (listof any/c)]) (listof any/c)
   (cond [(procedure? list-or-proc)  (list-or-proc xs)]
         [else                       list-or-proc]))
diff --git a/collects/plot/common/format.rkt b/collects/plot/common/format.rkt
index 24c142f040..8cb4c1b826 100644
--- a/collects/plot/common/format.rkt
+++ b/collects/plot/common/format.rkt
@@ -7,10 +7,7 @@
          "contract-doc.rkt"
          "math.rkt")
 
-(provide integer->superscript
-         real->decimal-string* real->string/trunc
-         digits-for-range real->plot-label ->plot-label
-         parse-format-string apply-formatter)
+(provide (all-defined-out))
 
 (define (string-map f str)
   (list->string (map f (string->list str))))
@@ -68,13 +65,6 @@
                  (remove-trailing-zeros (format "~a.~a" fst rst))
                  (integer->superscript (sub1 n)))]))
 
-#;
-(begin
-  (require rackunit)
-  (check-equal? (int-str->e-str "") "0")
-  (check-equal? (int-str->e-str "0") "0")
-  (check-equal? (int-str->e-str "10") "1×10\u00b9"))
-
 (define (frac-str->e-str str)
   (define n (string-length str))
   (let loop ([i 0])
@@ -87,15 +77,6 @@
                        [else
                         (format "~a.~a×10~a" fst rst (integer->superscript (- (add1 i))))])])))
 
-#;
-(begin
-  (require rackunit)
-  (check-equal? (frac-str->e-str "") "0")
-  (check-equal? (frac-str->e-str "0") "0")
-  (check-equal? (frac-str->e-str "00") "0")
-  (check-equal? (frac-str->e-str "1") "1×10\u207b\u00b9")
-  (check-equal? (frac-str->e-str "01") "1×10\u207b\u00b2"))
-
 (define (zero-string n)
   (list->string (build-list n (λ _ #\0))))
 
@@ -179,9 +160,9 @@
            (loop (+ i 2) (cons (string->symbol (substring str i (+ i 2))) fmt-list))]
           [else  (loop (+ i 1) (cons (substring str i (+ i 1)) fmt-list))])))
 
-(define (apply-formatter [formatter (symbol? . -> . (or/c string? #f))]
-                         [fmt-list (listof (or/c string? symbol?))]
-                         [d any/c]) (listof string?)
+(defproc (apply-formatter [formatter (symbol? . -> . (or/c string? #f))]
+                          [fmt-list (listof (or/c string? symbol?))]
+                          [d any/c]) (listof string?)
   (for/list ([fmt  (in-list fmt-list)])
     (cond [(eq? fmt '~~)  "~"]
           [(symbol? fmt)  (let ([val  (formatter fmt d)])
diff --git a/collects/plot/common/legend.rkt b/collects/plot/common/legend.rkt
index 60da57d813..444b14e0db 100644
--- a/collects/plot/common/legend.rkt
+++ b/collects/plot/common/legend.rkt
@@ -3,24 +3,31 @@
 ;; Functions that create legend entries and lists of legend entries.
 
 (require racket/class racket/match racket/list racket/string racket/sequence racket/contract
+         "contract.rkt"
+         "contract-doc.rkt"
          "format.rkt"
          "draw.rkt"
-         "utils.rkt"
-         "area.rkt")
+         "utils.rkt")
 
 (provide (all-defined-out))
 
+(struct legend-entry (label draw) #:transparent)
+
 ;; ===================================================================================================
 ;; Line legends
 
-(define (line-legend-entry label color width style)
+(defproc (line-legend-entry [label string?]
+                            [color plot-color/c] [width (>=/c 0)] [style plot-pen-style/c]
+                            ) legend-entry?
   (legend-entry label (λ (plot-area x-min x-max y-min y-max)
                         (define y (* 1/2 (+ y-min y-max)))
                         (send plot-area set-pen color width style)
                         (send plot-area set-alpha 1)
                         (send plot-area draw-line (vector x-min y) (vector x-max y)))))
 
-(define (line-legend-entries label zs z-labels colors widths styles)
+(defproc (line-legend-entries [label string?] [zs (listof real?)] [z-labels (listof string?)]
+                              [colors plot-colors/c] [widths pen-widths/c] [styles plot-pen-styles/c]
+                              ) (listof legend-entry?)
   (define hash
     (for/fold ([hash  empty]) ([z        (in-list zs)]
                                [z-label  (in-list z-labels)]
@@ -33,22 +40,27 @@
    (for/list ([entry  (in-list hash)])
      (match-define (cons args vs) entry)
      (apply line-legend-entry
-            (if (= 1 (length vs))
-                (format "~a = ~a" label (first vs))
-                (format "~a ∈ {~a}" label (string-join (reverse vs) ",")))
+            (cond [(= 1 (length vs))  (format "~a = ~a" label (first vs))]
+                  [else  (format "~a ∈ {~a}" label (string-join (reverse vs) ","))])
             args))))
 
 ;; ===================================================================================================
 ;; Rectangle legends
 
-(define (rectangle-legend-entry label fill-color fill-style line-color line-width line-style)
+(defproc (rectangle-legend-entry [label string?]
+                                 [fill-color plot-color/c] [fill-style plot-brush-style/c]
+                                 [line-color plot-color/c] [line-width (>=/c 0)]
+                                 [line-style plot-pen-style/c]) legend-entry?
   (legend-entry label (λ (plot-area x-min x-max y-min y-max)
                         (send plot-area set-brush fill-color fill-style)
                         (send plot-area set-pen line-color line-width line-style)
                         (send plot-area set-alpha 1)
                         (send plot-area draw-rectangle (vector x-min y-min) (vector x-max y-max)))))
 
-(define (rectangle-legend-entries label zs fill-colors fill-styles line-colors line-widths line-styles)
+(defproc (rectangle-legend-entries [label string?] [zs (listof real?)]
+                                   [fill-colors plot-colors/c] [fill-styles plot-brush-styles/c]
+                                   [line-colors plot-colors/c] [line-widths pen-widths/c]
+                                   [line-styles plot-pen-styles/c]) (listof legend-entry?)
   (define z-min (first zs))
   (define z-max (last zs))
   (define digits (digits-for-range z-min z-max))
@@ -73,9 +85,13 @@
 ;; ===================================================================================================
 ;; Interval legends
 
-(define (interval-legend-entry label fill-color fill-style line-color line-width line-style
-                               line1-color line1-width line1-style
-                               line2-color line2-width line2-style)
+(defproc (interval-legend-entry
+          [label string?]
+          [fill-color plot-color/c] [fill-style plot-brush-style/c]
+          [line-color plot-color/c] [line-width (>=/c 0)] [line-style plot-pen-style/c]
+          [line1-color plot-color/c] [line1-width (>=/c 0)] [line1-style plot-pen-style/c]
+          [line2-color plot-color/c] [line2-width (>=/c 0)] [line2-style plot-pen-style/c]
+          ) legend-entry?
   (legend-entry label (λ (plot-area x-min x-max y-min y-max)
                         (send plot-area set-alpha 1)
                         ;; rectangle
@@ -89,15 +105,18 @@
                         (send plot-area set-pen line2-color line2-width line2-style)
                         (send plot-area draw-line (vector x-min y-min) (vector x-max y-min)))))
 
-(define (interval-legend-entries label zs labels fill-colors fill-styles
-                                 line-colors line-widths line-styles
-                                 line1-colors line1-widths line1-styles
-                                 line2-colors line2-widths line2-styles)
+(defproc (interval-legend-entries
+          [label string?] [zs (listof real?)] [z-labels (listof string?)]
+          [fill-colors plot-colors/c] [fill-styles plot-brush-styles/c]
+          [line-colors plot-colors/c] [line-widths pen-widths/c] [line-styles plot-pen-styles/c]
+          [line1-colors plot-colors/c] [line1-widths pen-widths/c] [line1-styles plot-pen-styles/c]
+          [line2-colors plot-colors/c] [line2-widths pen-widths/c] [line2-styles plot-pen-styles/c]
+          ) (listof legend-entry?)
   (define hash
     (for/fold ([hash  empty]) ([za           (in-list zs)]
                                [zb           (in-list (rest zs))]
-                               [la           (in-list labels)]
-                               [lb           (in-list (rest labels))]
+                               [la           (in-list z-labels)]
+                               [lb           (in-list (rest z-labels))]
                                [fill-color   (in-cycle (maybe-apply/list fill-colors zs))]
                                [fill-style   (in-cycle (maybe-apply/list fill-styles zs))]
                                [line-color   (in-cycle (maybe-apply/list line-colors zs))]
@@ -128,9 +147,12 @@
                             line1-color line1-width line1-style
                             line2-color line2-width line2-style))))
 
-(define (contour-intervals-legend-entries label zs labels
-                                          fill-colors fill-styles line-colors line-widths line-styles
-                                          contour-colors contour-widths contour-styles)
+(defproc (contour-intervals-legend-entries
+          [label string?] [zs (listof real?)] [z-labels (listof string?)]
+          [fill-colors plot-colors/c] [fill-styles plot-brush-styles/c]
+          [line-colors plot-colors/c] [line-widths pen-widths/c] [line-styles plot-pen-styles/c]
+          [contour-colors plot-colors/c] [contour-widths pen-widths/c]
+          [contour-styles plot-pen-styles/c]) (listof legend-entry?)
   (define n (- (length zs) 2))
   (define ccs (append (list 0)
                       (sequence-take (in-cycle (maybe-apply/list contour-colors zs)) 0 n)
@@ -142,22 +164,25 @@
                       (sequence-take (in-cycle (maybe-apply/list contour-styles zs)) 0 n)
                       '(transparent)))
   
-  (interval-legend-entries label zs labels
+  (interval-legend-entries label zs z-labels
                            fill-colors fill-styles line-colors line-widths line-styles
                            ccs cws css (rest ccs) (rest cws) (rest css)))
 
 ;; ===================================================================================================
 ;; Point legends
 
-(define (point-legend-entry label symbol color size line-width)
+(defproc (point-legend-entry [label string?] [sym point-sym/c]
+                             [color plot-color/c] [size (>=/c 0)] [line-width (>=/c 0)]) legend-entry?
   (legend-entry label (λ (plot-area x-min x-max y-min y-max)
                         (send plot-area set-pen color line-width 'solid)
                         (send plot-area set-alpha 1)
                         (send plot-area draw-glyphs
                               (list (vector (* 1/2 (+ x-min x-max)) (* 1/2 (+ y-min y-max))))
-                              symbol size))))
+                              sym size))))
 
-(define (vector-field-legend-entry label color line-width line-style)
+(defproc (vector-field-legend-entry [label string?] [color plot-color/c]
+                                    [line-width (>=/c 0)] [line-style plot-pen-style/c]
+                                    ) legend-entry?
   (legend-entry label (λ (plot-area x-min x-max y-min y-max)
                         (send plot-area set-pen color line-width line-style)
                         (send plot-area set-alpha 1)
diff --git a/collects/plot/common/marching-squares.rkt b/collects/plot/common/marching-squares.rkt
index 9f609274aa..c21aa3b4ec 100644
--- a/collects/plot/common/marching-squares.rkt
+++ b/collects/plot/common/marching-squares.rkt
@@ -1,10 +1,12 @@
 #lang racket/base
 
-(require racket/flonum racket/fixnum racket/list racket/match racket/unsafe/ops
+(require racket/flonum racket/fixnum racket/list racket/match racket/unsafe/ops racket/contract
          (for-syntax racket/base)
-         "math.rkt")
+         "math.rkt"
+         "contract-doc.rkt")
 
-(provide heights->lines heights->polys)
+(provide heights->lines heights->polys
+         heights->lines:doc heights->polys:doc)
 
 ;; Returns the interpolated distance of z from za toward zb
 ;; Examples: if z = za, this returns 0.0
@@ -141,7 +143,9 @@ above.
   (let ([id  (exact->inexact id)] ...)
     body0 body ...))
 
-(define (heights->lines xa xb ya yb z z1 z2 z3 z4)
+(defproc (heights->lines [xa real?] [xb real?] [ya real?] [yb real?]
+                         [z real?] [z1 real?] [z2 real?] [z3 real?] [z4 real?]
+                         ) (list/c (vector/c real? real? real?) (vector/c real? real? real?))
   (check-all-real! 'heights->lines xa xb ya yb z z1 z2 z3 z4)
   (let-exact->inexact
    (xa xb ya yb z z1 z2 z3 z4)
@@ -585,7 +589,10 @@ above.
           polys2210 polys2211 polys2212 
           polys2220 polys2221 polys2222))
 
-(define (heights->polys xa xb ya yb za zb z1 z2 z3 z4)
+(defproc (heights->polys [xa real?] [xb real?] [ya real?] [yb real?]
+                         [za real?] [zb real?]
+                         [z1 real?] [z2 real?] [z3 real?] [z4 real?]
+                         ) (listof (vector/c real? real? real?))
   (check-all-real! xa xb ya yb za zb z1 z2 z3 z4)
   (let-exact->inexact
    (xa xb ya yb za zb z1 z2 z3 z4)
diff --git a/collects/plot/common/math.rkt b/collects/plot/common/math.rkt
index 3a7297de4a..a1db54bfe0 100644
--- a/collects/plot/common/math.rkt
+++ b/collects/plot/common/math.rkt
@@ -3,37 +3,38 @@
 (require racket/contract racket/unsafe/ops
          "contract-doc.rkt")
 
+(provide (all-defined-out))
+
 ;; ===================================================================================================
 ;; Flonums
 
-(provide nan? infinite? special? flblend flatan2 flsum flmodulo fldistance)
+(defproc (nan? [x any/c]) boolean?
+  (eqv? x +nan.0))
 
-(define (nan? x) (eqv? x +nan.0))
-
-(define (infinite? x)
+(defproc (infinite? [x any/c]) boolean?
   (and (flonum? x) (or (unsafe-fl= x +inf.0) (unsafe-fl= x -inf.0))))
 
-(define (special? x)
+(defproc (special? [x any/c]) boolean?
   (and (flonum? x) (or (unsafe-fl= x +inf.0) (unsafe-fl= x -inf.0) (eqv? x +nan.0))))
 
-(define (flblend x y α)
+(defproc (flblend [x flonum?] [y flonum?] [α flonum?]) flonum?
   (cond [(not (flonum? x))  (raise-type-error 'flblend "flonum" 0 x y α)]
         [(not (flonum? y))  (raise-type-error 'flblend "flonum" 1 x y α)]
         [(not (flonum? α))  (raise-type-error 'flblend "flonum" 2 x y α)]
         [else  (unsafe-fl+ (unsafe-fl* α x) (unsafe-fl* (unsafe-fl- 1 α) y))]))
 
-(define (flatan2 y x)
+(defproc (flatan2 [y flonum?] [x flonum?]) flonum?
   (cond [(not (flonum? y))  (raise-type-error 'flatan2 "flonum" 0 x y)]
         [(not (flonum? x))  (raise-type-error 'flatan2 "flonum" 1 x y)]
         [else  (exact->inexact (atan2 y x))]))
 
-(define (flsum f xs)
+(defproc (flsum [f (any/c . -> . flonum?)] [xs (listof any/c)]) flonum?
   (define ys (map f xs))
   (cond [(not (andmap flonum? ys))  (raise-type-error 'sum "any -> flonum" f)]
         [else  (for/fold ([sum 0.0]) ([y  (in-list ys)])
                  (unsafe-fl+ sum y))]))
 
-(define (flmodulo x y)
+(defproc (flmodulo [x flonum?] [y flonum?]) flonum?
   (cond [(not (flonum? x))  (raise-type-error 'real-modulo "flonum" 0 x y)]
         [(not (flonum? y))  (raise-type-error 'real-modulo "flonum" 1 x y)]
         [else  (unsafe-fl- x (unsafe-fl* y (unsafe-flfloor (unsafe-fl/ x y))))]))
@@ -56,20 +57,15 @@
 ;; ===================================================================================================
 ;; Reals
 
-(provide regular? equal?* min* max*
-         degrees->radians radians->degrees
-         blend atan2 sum real-modulo distance
-         floor-log/base ceiling-log/base
-         polar->cartesian 3d-polar->3d-cartesian)
-
-(define (regular? x) (and (real? x) (not (special? x))))
+(defproc (regular? [x any/c]) boolean?
+  (and (real? x) (not (special? x))))
 
 (define equal?*
   (case-lambda
     [()   #t]
     [(x)  #t]
     [xs   (and (equal? (car xs) (cadr xs))
-               (equal?* (cdr xs)))]))
+               (apply equal?* (cdr xs)))]))
 
 (define-syntax-rule (min2* x y)
   (cond [(x . < . y)  x]
@@ -110,32 +106,32 @@
 (define 180/pi (/ 180 pi))
 (define pi/180 (/ pi 180))
 
-(define (degrees->radians d)
+(defproc (degrees->radians [d real?]) real?
   (cond [(not (real? d))  (raise-type-error 'degrees->radians "real number" d)]
         [else  (* d pi/180)]))
 
-(define (radians->degrees r)
+(defproc (radians->degrees [r real?]) real?
   (cond [(not (real? r))  (raise-type-error 'radians->degrees "real number" r)]
         [else  (* r 180/pi)]))
 
-(define (blend x y α)
+(defproc (blend [x real?] [y real?] [α real?]) real?
   (cond [(not (real? x))  (raise-type-error 'blend "real number" 0 x y α)]
         [(not (real? y))  (raise-type-error 'blend "real number" 1 x y α)]
         [(not (real? α))  (raise-type-error 'blend "real number" 2 x y α)]
         [else  (+ (* α x) (* (- 1 α) y))]))
 
-(define (atan2 y x)
+(defproc (atan2 [y real?] [x real?]) real?
   (cond [(not (real? y))  (raise-type-error 'atan2 "real number" 0 y x)]
         [(not (real? x))  (raise-type-error 'atan2 "real number" 1 y x)]
         [(and (zero? y) (zero? x))  0]
         [else  (atan y x)]))
 
-(define (sum f xs)
+(defproc (sum [f (any/c . -> . real?)] [xs (listof any/c)]) real?
   (define ys (map f xs))
   (cond [(not (andmap real? ys))  (raise-type-error 'sum "any -> real" f)]
         [else  (apply + ys)]))
 
-(define (real-modulo x y)
+(defproc (real-modulo [x real?] [y real?]) real?
   (cond [(not (real? x))  (raise-type-error 'real-modulo "real number" 0 x y)]
         [(not (real? y))  (raise-type-error 'real-modulo "real number" 1 x y)]
         [else  (- x (* y (floor (/ x y))))]))
@@ -154,7 +150,7 @@
     [xs  (cond [(not (andmap real? xs)) (raise-type-error 'distance "real numbers" xs)]
                [else  (sqrt (sum sqr xs))])]))
 
-(define (floor-log/base b x)
+(defproc (floor-log/base [b (and/c exact-integer? (>=/c 2))] [x (>/c 0)]) exact-integer?
   (cond [(not (and (exact-integer? b) (b . >= . 2)))  (raise-type-error 'floor-log/base
                                                                         "exact integer >= 2" 0 b x)]
         [(not (and (real? x) (x . > . 0)))  (raise-type-error 'floor-log/base "real > 0" 1 b x)]
@@ -166,13 +162,13 @@
                               [else  y]))]
                      [else  y])]))
 
-(define (ceiling-log/base b x)
+(defproc (ceiling-log/base [b (and/c exact-integer? (>=/c 2))] [x (>/c 0)]) exact-integer?
   (cond [(not (and (exact-integer? b) (b . >= . 2)))  (raise-type-error 'floor-log/base
                                                                         "exact integer >= 2" 0 b x)]
         [(not (and (real? x) (x . > . 0)))  (raise-type-error 'floor-log/base "real > 0" 1 b x)]
         [else  (inexact->exact (ceiling (/ (log (abs x)) (log b))))]))
 
-(define (polar->cartesian θ r)
+(defproc (polar->cartesian [θ real?] [r real?]) (vector/c real? real?)
   (cond [(not (real? θ))  (raise-type-error 'polar->cartesian "real number" 0 θ r)]
         [(not (real? r))  (raise-type-error 'polar->cartesian "real number" 1 θ r)]
         [else  (let ([θ  (exact->inexact θ)]
@@ -180,7 +176,7 @@
                  (vector (unsafe-fl* r (unsafe-flcos θ))
                          (unsafe-fl* r (unsafe-flsin θ))))]))
 
-(define (3d-polar->3d-cartesian θ ρ r)
+(defproc (3d-polar->3d-cartesian [θ real?] [ρ real?] [r real?]) (vector/c real? real? real?)
   (cond [(not (real? θ))  (raise-type-error '3d-polar->3d-cartesian "real number" 0 θ ρ r)]
         [(not (real? ρ))  (raise-type-error '3d-polar->3d-cartesian "real number" 1 θ ρ r)]
         [(not (real? r))  (raise-type-error '3d-polar->3d-cartesian "real number" 2 θ ρ r)]
@@ -195,10 +191,8 @@
 ;; ===================================================================================================
 ;; Vectors
 
-(provide vcross v+ v- vneg v* v/ vmag^2 vmag vnormalize vdot vregular? v= vcenter
-         vregular-sublists vnormal)
-
-(define (vcross v1 v2)
+(defproc (vcross [v1 (vector/c real? real? real?)] [v2 (vector/c real? real? real?)]
+                 ) (vector/c real? real? real?)
   (match v1
     [(vector (? real? x1) (? real? y1) (? real? z1))
      (match v2
@@ -253,21 +247,26 @@
        [_  (raise-type-error name "vector of 3 reals" 1 v1 v2)])]
     [_  (vmap2 name f v1 v2)]))
 
-(define (v+ v1 v2) (unrolled-vmap2 'v+ + v1 v2))
-(define (v- v1 v2) (unrolled-vmap2 'v- - v1 v2))
-(define (vneg v) (unrolled-vmap 'vneg - v))
+(defproc (v+ [v1 (vectorof real?)] [v2 (vectorof real?)]) (vectorof real?)
+  (unrolled-vmap2 'v+ + v1 v2))
 
-(define (v* v c)
+(defproc (v- [v1 (vectorof real?)] [v2 (vectorof real?)]) (vectorof real?)
+  (unrolled-vmap2 'v- - v1 v2))
+
+(defproc (vneg [v (vectorof real?)]) (vectorof real?)
+  (unrolled-vmap 'vneg - v))
+
+(defproc (v* [v (vectorof real?)] [c real?]) (vectorof real?)
   (cond [(real? c)  (define-syntax-rule (f x) (* x c))
                     (unrolled-vmap 'v* f v)]
         [else  (raise-type-error 'v* "real" 1 v c)]))
 
-(define (v/ v c)
+(defproc (v/ [v (vectorof real?)] [c real?]) (vectorof real?)
   (cond [(real? c)  (define-syntax-rule (f x) (/ x c))
                     (unrolled-vmap 'v/ f v)]
         [else  (raise-type-error 'v/ "real" 1 v c)]))
 
-(define (vmag^2 v)
+(defproc (vmag^2 [v (vectorof real?)]) real?
   (match v
     [(vector (? real? x) (? real? y))              (+ (* x x) (* y y))]
     [(vector (? real? x) (? real? y) (? real? z))  (+ (* x x) (* y y) (* z z))]
@@ -277,17 +276,19 @@
           (+ mag (cond [(real? x)    (* x x)]
                        [else  (raise-type-error 'vmag^2 "vector of reals" v)])))]))
 
-(define (vmag v) (sqrt (vmag^2 v)))
+(defproc (vmag [v (vectorof real?)]) real?
+  (sqrt (vmag^2 v)))
 
-(define (vnormalize v)
+(defproc (vnormalize [v (vectorof real?)]) (vectorof real?)
   (match v
     [(vector (? real? x) (? real? y))              (define m (sqrt (+ (* x x) (* y y))))
-                                                   (vector (/ x m) (/ y m))]
+                                                   (if (= m 0) v (vector (/ x m) (/ y m)))]
     [(vector (? real? x) (? real? y) (? real? z))  (define m (sqrt (+ (* x x) (* y y) (* z z))))
-                                                   (vector (/ x m) (/ y m) (/ z m))]
-    [_  (v/ v (vmag v))]))
+                                                   (if (= m 0) v (vector (/ x m) (/ y m) (/ z m)))]
+    [_  (define m (vmag v))
+        (if (= m 0) v (v/ v m))]))
 
-(define (vdot v1 v2)
+(defproc (vdot [v1 (vectorof real?)] [v2 (vectorof real?)]) real?
   (match v1
     [(vector (? real? x1) (? real? y1))
      (match v2
@@ -312,7 +313,7 @@
 (define-syntax-rule (unsafe-flregular? x)
   (not (unsafe-flspecial? x)))
 
-(define (vregular? v)
+(defproc (vregular? [v (vectorof real?)]) boolean?
   (match v
     [(vector (? real? x) (? real? y))
      (cond [(flonum? x)  (unsafe-flregular? x)]
@@ -329,7 +330,7 @@
               (break #f)))
           #t)]))
 
-(define (v= v1 v2)
+(defproc (v= [v1 (vectorof real?)] [v2 (vectorof real?)]) boolean?
   (match v1
     [(vector (? real? x1) (? real? y1))
      (match v2
@@ -350,7 +351,7 @@
                 (raise-type-error 'v= "vector of real" 0 v1 v2)))
           #t)]))
 
-(define (vcenter vs)
+(defproc (vcenter [vs (listof (vectorof real?))]) (vectorof real?)
   (match vs
     [(list (vector xs ys) ...)
      (define mins (vector (apply min* xs) (apply min* ys)))
@@ -485,22 +486,9 @@
                     [x2  (in-list (rest xs))])
            (ivl x1 x2))]))
 
-(provide
- (contract-out (struct ivl ([min (or/c real? #f)] [max (or/c real? #f)]))
-               [ivl-meet (->* () () #:rest (listof ivl?) ivl?)]
-               [ivl-join (->* () () #:rest (listof ivl?) ivl?)])
- empty-ivl unknown-ivl ivl-inexact->exact bounds->intervals
- ivl-empty? ivl-known? ivl-regular? ivl-singular? ivl-zero-length? ivl-contains?)
-
 ;; ===================================================================================================
 ;; Rectangles
 
-(provide
- empty-rect unknown-rect bounding-rect rect-inexact->exact 
- rect-empty? rect-known? rect-regular? rect-zero-area? rect-singular? rect-contains?
- (contract-out [rect-meet (->* () () #:rest (listof (vectorof ivl?)) (vectorof ivl?))]
-               [rect-join (->* () () #:rest (listof (vectorof ivl?)) (vectorof ivl?))]))
-
 (define vector-andmap
   (case-lambda
     [(f v)  (let/ec break
diff --git a/collects/plot/common/parameters.rkt b/collects/plot/common/parameters.rkt
index 9c660e53f1..d9a58a4d02 100644
--- a/collects/plot/common/parameters.rkt
+++ b/collects/plot/common/parameters.rkt
@@ -2,7 +2,7 @@
 
 ;; Parameters that control the look and behavior of plots.
 
-(require racket/contract unstable/parameter-group
+(require racket/contract unstable/parameter-group unstable/latent-contract
          "contract.rkt"
          "contract-doc.rkt"
          "draw.rkt"
@@ -43,6 +43,8 @@
 (defparam plot-x-max-ticks exact-positive-integer? 5)
 (defparam plot-y-max-ticks exact-positive-integer? 5)
 (defparam plot-z-max-ticks exact-positive-integer? 8)
+(defparam plot-d-max-ticks exact-positive-integer? 5)
+(defparam plot-r-max-ticks exact-positive-integer? 8)
 
 (defparam plot-x-far-max-ticks exact-positive-integer? 5)
 (defparam plot-y-far-max-ticks exact-positive-integer? 5)
@@ -51,44 +53,35 @@
 (defparam plot-decorations? boolean? #t)
 
 (define-parameter-group plot-axes?
-  (plot-x-axis?
-   plot-y-axis?
-   plot-z-axis?
-   plot-x-far-axis?
-   plot-y-far-axis?
-   plot-z-far-axis?)
+  (plot-x-axis? plot-x-far-axis?
+   plot-y-axis? plot-y-far-axis?
+   plot-z-axis? plot-z-far-axis?)
   #:struct list)
 
 (define-parameter-group plot-max-ticks
-  (plot-x-max-ticks
-   plot-y-max-ticks
-   plot-z-max-ticks
-   plot-x-far-max-ticks
-   plot-y-far-max-ticks
-   plot-z-far-max-ticks)
+  (plot-x-max-ticks plot-x-far-max-ticks
+   plot-y-max-ticks plot-y-far-max-ticks
+   plot-z-max-ticks plot-z-far-max-ticks
+   plot-d-max-ticks
+   plot-r-max-ticks)
   #:struct list)
 
 (define-parameter-group plot-appearance
    (plot-width
     plot-height
-    plot-foreground
-    plot-background
-    plot-foreground-alpha
-    plot-background-alpha
-    plot-line-width
-    plot-tick-size
-    plot-font-size
-    plot-font-family
-    plot-legend-anchor
-    plot-legend-box-alpha
-    plot-axes?
-    plot-max-ticks
-    plot-decorations?
+    plot-foreground plot-foreground-alpha
+    plot-background plot-background-alpha
+    plot-line-width plot-tick-size
+    plot-font-size plot-font-family
+    plot-legend-anchor plot-legend-box-alpha
+    plot-axes? plot-max-ticks plot-decorations?
     plot-animating?))
 
-(define (pen-gap) (* 2 (plot-line-width)))
+(defproc (pen-gap) real? #:document-body
+  (* 2 (plot-line-width)))
 
-(defproc (animated-samples [samples (and/c exact-integer? (>=/c 2))]) (and/c exact-integer? (>=/c 2))
+(defproc (animated-samples [samples (and/c exact-integer? (>=/c 2))]
+                           ) (and/c exact-integer? (>=/c 2)) #:document-body
   (cond [(plot-animating?)  (max 2 (ceiling (* 1/4 samples)))]
         [else  samples]))
 
@@ -138,38 +131,56 @@
 (defparam plot-x-transform axis-transform/c id-transform)
 (defparam plot-y-transform axis-transform/c id-transform)
 (defparam plot-z-transform axis-transform/c id-transform)
+(defparam plot-d-transform axis-transform/c id-transform)
+(defparam plot-r-transform axis-transform/c id-transform)
 
 (defparam plot-x-ticks ticks? (linear-ticks))
 (defparam plot-y-ticks ticks? (linear-ticks))
 (defparam plot-z-ticks ticks? (linear-ticks))
+(defparam plot-d-ticks ticks? (linear-ticks))
+(defparam plot-r-ticks ticks? (linear-ticks))
 
 (defparam plot-x-far-ticks ticks? (ticks-mimic plot-x-ticks))
 (defparam plot-y-far-ticks ticks? (ticks-mimic plot-y-ticks))
 (defparam plot-z-far-ticks ticks? (ticks-mimic plot-z-ticks))
 
-(struct axis (transform ticks far-ticks) #:transparent)
+(struct axis (transform ticks) #:transparent)
+(define-parameter-group plot-d-axis (plot-d-transform plot-d-ticks) #:struct axis)
+(define-parameter-group plot-r-axis (plot-r-transform plot-r-ticks) #:struct axis)
 
-(define-parameter-group plot-x-axis (plot-x-transform plot-x-ticks plot-x-far-ticks) #:struct axis)
-(define-parameter-group plot-y-axis (plot-y-transform plot-y-ticks plot-y-far-ticks) #:struct axis)
-(define-parameter-group plot-z-axis (plot-z-transform plot-z-ticks plot-z-far-ticks) #:struct axis)
-(define-parameter-group plot-axes (plot-x-axis plot-y-axis plot-z-axis) #:struct list)
+(struct dual-axis (transform ticks far-ticks) #:transparent)
+(define-parameter-group plot-x-axis (plot-x-transform plot-x-ticks plot-x-far-ticks)
+  #:struct dual-axis)
+(define-parameter-group plot-y-axis (plot-y-transform plot-y-ticks plot-y-far-ticks)
+  #:struct dual-axis)
+(define-parameter-group plot-z-axis (plot-z-transform plot-z-ticks plot-z-far-ticks)
+  #:struct dual-axis)
 
-(defproc (default-x-ticks [x-min real?] [x-max real?]) (listof tick?)
+(define-parameter-group plot-axes (plot-x-axis plot-y-axis plot-z-axis plot-d-axis plot-r-axis)
+  #:struct list)
+
+(defproc (default-x-ticks [x-min real?] [x-max real?]) (listof tick?) #:document-body
   ((plot-x-ticks) x-min x-max (plot-x-max-ticks)))
 
-(defproc (default-y-ticks [y-min real?] [y-max real?]) (listof tick?)
+(defproc (default-y-ticks [y-min real?] [y-max real?]) (listof tick?) #:document-body
   ((plot-y-ticks) y-min y-max (plot-y-max-ticks)))
 
-(defproc (default-z-ticks [z-min real?] [z-max real?]) (listof tick?)
+(defproc (default-z-ticks [z-min real?] [z-max real?]) (listof tick?) #:document-body
   ((plot-z-ticks) z-min z-max (plot-z-max-ticks)))
 
-(defproc (default-x-far-ticks [x-min real?] [x-max real?]) (listof tick?)
+(defproc (default-d-ticks [d-min real?] [d-max real?]) (listof tick?) #:document-body
+  ((plot-d-ticks) d-min d-max (plot-d-max-ticks)))
+
+(defproc (default-r-ticks [r-min real?] [r-max real?]) (listof tick?) #:document-body
+  ((plot-r-ticks) r-min r-max (plot-r-max-ticks)))
+
+(defproc (default-x-far-ticks [x-min real?] [x-max real?]) (listof tick?) #:document-body
   ((plot-x-far-ticks) x-min x-max (plot-x-far-max-ticks)))
 
-(defproc (default-y-far-ticks [y-min real?] [y-max real?]) (listof tick?)
+(defproc (default-y-far-ticks [y-min real?] [y-max real?]) (listof tick?) #:document-body
   ((plot-y-far-ticks) y-min y-max (plot-y-far-max-ticks)))
 
-(defproc (default-z-far-ticks [z-min real?] [z-max real?]) (listof tick?)
+(defproc (default-z-far-ticks [z-min real?] [z-max real?]) (listof tick?) #:document-body
   ((plot-z-far-ticks) z-min z-max (plot-z-far-max-ticks)))
 
 ;; ===================================================================================================
@@ -231,11 +242,11 @@
 
 ;; Contours
 
-(defproc (default-contour-colors [zs (listof real?)]) (listof plot-color/c)
+(defproc (default-contour-colors [zs (listof real?)]) (listof plot-color/c) #:document-body
   (color-seq* (list (->pen-color 5) (->pen-color 0) (->pen-color 1))
               (length zs)))
 
-(defproc (default-contour-fill-colors [zs (listof real?)]) (listof plot-color/c)
+(defproc (default-contour-fill-colors [zs (listof real?)]) (listof plot-color/c) #:document-body
   (color-seq* (list (->brush-color 5) (->brush-color 0) (->brush-color 1))
               (sub1 (length zs))))
 
@@ -265,10 +276,12 @@
 (defparam x-axis-ticks? boolean? #t)
 (defparam y-axis-ticks? boolean? #t)
 (defparam z-axis-ticks? boolean? #t)
+(defparam polar-axes-ticks? boolean? #t)
 
 (defparam x-axis-labels? boolean? #f)
 (defparam y-axis-labels? boolean? #f)
 (defparam z-axis-labels? boolean? #f)
+(defparam polar-axes-labels? boolean? #t)
 
 (defparam x-axis-far? boolean? #f)
 (defparam y-axis-far? boolean? #f)
@@ -277,10 +290,9 @@
 (defparam x-axis-alpha (real-in 0 1) 1)
 (defparam y-axis-alpha (real-in 0 1) 1)
 (defparam z-axis-alpha (real-in 0 1) 1)
+(defparam polar-axes-alpha (real-in 0 1) 1/2)
 
 (defparam polar-axes-number exact-positive-integer? 12)
-(defparam polar-axes-ticks? boolean? #t)
-(defparam polar-axes-max-ticks exact-positive-integer? 8)
 
 (defparam label-anchor anchor/c 'left)
 (defparam label-angle real? 0)
@@ -304,11 +316,11 @@
 
 ;; Isosurfaces
 
-(defproc (default-isosurface-colors [zs (listof real?)]) (listof plot-color/c)
+(defproc (default-isosurface-colors [zs (listof real?)]) (listof plot-color/c) #:document-body
   (color-seq* (list (->brush-color 5) (->brush-color 0) (->brush-color 1))
               (length zs)))
 
-(defproc (default-isosurface-line-colors [zs (listof real?)]) (listof plot-color/c)
+(defproc (default-isosurface-line-colors [zs (listof real?)]) (listof plot-color/c) #:document-body
   (color-seq* (list (->pen-color 5) (->pen-color 0) (->pen-color 1))
               (length zs)))
 
diff --git a/collects/plot/common/plot-element.rkt b/collects/plot/common/plot-element.rkt
index b021f6ac8a..67f0cdcb12 100644
--- a/collects/plot/common/plot-element.rkt
+++ b/collects/plot/common/plot-element.rkt
@@ -2,6 +2,7 @@
 
 (require racket/list racket/contract racket/match
          "math.rkt"
+         "ticks.rkt"
          "contract.rkt"
          "contract-doc.rkt"
          "parameters.rkt"
@@ -14,58 +15,69 @@
 (struct renderer2d plot-element (render-proc) #:transparent)
 (struct renderer3d plot-element (render-proc) #:transparent)
 
+(defcontract bounds-fun/c ((vectorof ivl?) . -> . (vectorof ivl?)))
+(defcontract ticks-fun/c ((vectorof ivl?) . -> . any))
+
 ;; ===================================================================================================
 ;; Common field values
 
-(define (default-ticks-fun r)
-  (match r
-    [(vector (ivl xa xb) (ivl ya yb))
-     (values (default-x-ticks xa xb) (default-x-far-ticks xa xb)
-             (default-y-ticks ya yb) (default-y-far-ticks ya yb))]
-    [(vector (ivl xa xb) (ivl ya yb) (ivl za zb))
-     (values (default-x-ticks xa xb) (default-x-far-ticks xa xb)
-             (default-y-ticks ya yb) (default-y-far-ticks ya yb)
+(defthing default-ticks-fun ticks-fun/c
+  (λ (r)
+    (match r
+      [(vector (ivl xa xb) (ivl ya yb))
+       (values (default-x-ticks xa xb) (default-x-far-ticks xa xb)
+               (default-y-ticks ya yb) (default-y-far-ticks ya yb))]
+      [(vector (ivl xa xb) (ivl ya yb) (ivl za zb))
+       (values (default-x-ticks xa xb) (default-x-far-ticks xa xb)
+               (default-y-ticks ya yb) (default-y-far-ticks ya yb)
              (default-z-ticks za zb) (default-z-far-ticks za zb))]
-    [_  (raise-type-error 'default-ticks-fun "2- or 3-vector of ivl" r)]))
+      [_  (raise-type-error 'default-ticks-fun "2- or 3-vector of ivl" r)])))
 
-(define ((function-bounds-fun f samples) r)
-  (match-define (vector xi yi) r)
-  (cond [(ivl-known? xi)
-         (match-define (ivl x-min x-max) xi)
-         (match-define (list xs ys) (f x-min x-max samples))
-         (define rys (filter regular? ys))
-         (cond [(not (empty? rys))  (vector xi (ivl (apply min* rys) (apply max* rys)))]
-               [else  r])]
-        [else  r]))
+(defproc (function-bounds-fun [f sampler/c] [samples exact-nonnegative-integer?]) bounds-fun/c
+  (λ (r)
+    (match-define (vector xi yi) r)
+    (cond [(ivl-known? xi)
+           (match-define (ivl x-min x-max) xi)
+           (match-define (list xs ys) (f x-min x-max samples))
+           (define rys (filter regular? ys))
+           (cond [(not (empty? rys))  (vector xi (ivl (apply min* rys) (apply max* rys)))]
+                 [else  r])]
+          [else  r])))
 
-(define ((inverse-bounds-fun f samples) r)
-  (match-define (vector xi yi) r)
-  (cond [(ivl-known? yi)
-         (match-define (ivl y-min y-max) yi)
-         (match-define (list ys xs) (f y-min y-max samples))
-         (define rxs (filter regular? xs))
-         (cond [(not (empty? rxs))  (vector (ivl (apply min* rxs) (apply max* rxs)) yi)]
-               [else  r])]
-        [else  r]))
+(defproc (inverse-bounds-fun [f sampler/c] [samples exact-nonnegative-integer?]) bounds-fun/c
+  (λ (r)
+    (match-define (vector xi yi) r)
+    (cond [(ivl-known? yi)
+           (match-define (ivl y-min y-max) yi)
+           (match-define (list ys xs) (f y-min y-max samples))
+           (define rxs (filter regular? xs))
+           (cond [(not (empty? rxs))  (vector (ivl (apply min* rxs) (apply max* rxs)) yi)]
+                 [else  r])]
+          [else  r])))
 
-(define ((function-interval-bounds-fun f1 f2 samples) r)
-  (rect-join ((function-bounds-fun f1 samples) r)
-             ((function-bounds-fun f2 samples) r)))
+(defproc (function-interval-bounds-fun [f1 sampler/c] [f2 sampler/c]
+                                       [samples exact-nonnegative-integer?]) bounds-fun/c
+  (λ (r)
+    (rect-join ((function-bounds-fun f1 samples) r)
+               ((function-bounds-fun f2 samples) r))))
 
-(define ((inverse-interval-bounds-fun f1 f2 samples) r)
-  (rect-join ((inverse-bounds-fun f1 samples) r)
-             ((inverse-bounds-fun f2 samples) r)))
+(defproc (inverse-interval-bounds-fun [f1 sampler/c] [f2 sampler/c]
+                                      [samples exact-nonnegative-integer?]) bounds-fun/c
+  (λ (r)
+    (rect-join ((inverse-bounds-fun f1 samples) r)
+               ((inverse-bounds-fun f2 samples) r))))
 
-(define ((surface3d-bounds-fun f samples) r)
-  (match-define (vector xi yi zi) r)
-  (cond [(and (ivl-known? xi) (ivl-known? yi))
-         (match-define (ivl x-min x-max) xi)
-         (match-define (ivl y-min y-max) yi)
-         (match-define (list xs ys zss) (f x-min x-max samples y-min y-max samples))
-         (define zs (filter regular? (2d-sample->list zss)))
-         (cond [(not (empty? zs)) (vector xi yi (ivl (apply min* zs) (apply max* zs)))]
-               [else  r])]
-        [else  r]))
+(defproc (surface3d-bounds-fun [f 2d-sampler/c] [samples exact-nonnegative-integer?]) bounds-fun/c
+  (λ (r)
+    (match-define (vector xi yi zi) r)
+    (cond [(and (ivl-known? xi) (ivl-known? yi))
+           (match-define (ivl x-min x-max) xi)
+           (match-define (ivl y-min y-max) yi)
+           (match-define (list xs ys zss) (f x-min x-max samples y-min y-max samples))
+           (define zs (filter regular? (2d-sample->list zss)))
+           (cond [(not (empty? zs)) (vector xi yi (ivl (apply min* zs) (apply max* zs)))]
+                 [else  r])]
+          [else  r])))
 
 ;; ===================================================================================================
 ;; Fixpoint computation of bounding rectangles
diff --git a/collects/plot/common/sample.rkt b/collects/plot/common/sample.rkt
index 2c56d2e4a1..1f7f63a4b0 100644
--- a/collects/plot/common/sample.rkt
+++ b/collects/plot/common/sample.rkt
@@ -9,7 +9,7 @@
 
 (provide (all-defined-out))
 
-(define (build-linear-seq start step num)
+(defproc (build-linear-seq [start real?] [step real?] [num exact-nonnegative-integer?]) (listof real?)
   (for/list ([n  (in-range num)])
     (+ start (* n step))))
 
@@ -49,6 +49,13 @@
                (blend (vector-ref pts (add1 i)) (vector-ref pts i) f)))
          int-parts frac-parts)))
 
+(defproc (nonlinear-seq [start real?] [end real?] [num exact-nonnegative-integer?]
+                        [transform axis-transform/c]
+                        [#:start? start? boolean? #t]
+                        [#:end? end? boolean? #t]) (listof real?)
+  (match-define (invertible-function _ finv) (apply-transform transform start end))
+  (map finv (linear-seq start end num #:start? start? #:end? end?)))
+
 (struct mapped-function (f fmap) #:transparent
   #:property prop:procedure
   (λ (g x) ((mapped-function-f g) x)))
@@ -60,85 +67,80 @@
     [(? mapped-function?)  ((mapped-function-fmap f) xs)]
     [_  (map f xs)]))
 
-(defproc (nonlinear-seq [start real?] [end real?] [num exact-nonnegative-integer?]
-                        [transform axis-transform/c]
-                        [#:start? start? boolean? #t]
-                        [#:end? end? boolean? #t]) (listof real?)
-  (match-define (invertible-function _ finv) (apply-transform transform start end))
-  (map finv (linear-seq start end num #:start? start? #:end? end?)))
+;; ===================================================================================================
+;; Making memoized samplers
 
-(define 2pi (* 2 pi))
+(defcontract sample/c (list/c (listof real?) (listof real?)))
+(defcontract sampler/c (real? real? exact-nonnegative-integer? . -> . sample/c))
 
-(define ((2d-polar->3d-function f) x y z)
-  (let ([x  (exact->inexact x)]
-        [y  (exact->inexact y)]
-        [z  (exact->inexact z)])
-    (define-values (θ ρ)
-      (cond [(and (fl= x 0.0) (fl= y 0.0))  (values 0.0 0.0)]
-            [else  (values (flmodulo (flatan2 y x) 2pi)
-                           (flatan (fl/ z (distance x y))))]))
-    (define r (exact->inexact (f θ ρ)))
-    (fl- r (distance x y z))))
+(defcontract 2d-sample/c (list/c (listof real?) (listof real?)
+                                 (vectorof (vectorof real?))))
+(defcontract 2d-sampler/c (real? real? exact-nonnegative-integer?
+                                 real? real? exact-nonnegative-integer?
+                                 . -> . 2d-sample/c))
 
-(define (sample-parametric f t-min t-max samples)
-  (map* f (linear-seq t-min t-max samples)))
+(defcontract 3d-sample/c (list/c (listof real?) (listof real?) (listof real?)
+                                 (vectorof (vectorof (vectorof real?)))))
+(defcontract 3d-sampler/c (real? real? exact-nonnegative-integer?
+                                 real? real? exact-nonnegative-integer?
+                                 real? real? exact-nonnegative-integer?
+                                 . -> . 3d-sample/c))
 
-(define (sample-polar f θ-min θ-max samples)
-  (define θs (linear-seq θ-min θ-max samples))
-  (define rs (map* f θs))
-  (map polar->cartesian θs rs))
+(defproc (make-function->sampler [transform-thnk (-> axis-transform/c)]
+                                 ) ((real? . -> . real?) . -> . sampler/c)
+  (λ (f)
+    (define memo (make-hash))
+    (λ (x-min x-max x-samples)
+      (define tx (transform-thnk))
+      (hash-ref! memo (vector x-min x-max x-samples tx)
+                 (λ ()
+                   (define xs (nonlinear-seq x-min x-max x-samples tx))
+                   (list xs (map* f xs)))))))
 
-(define (sample-2d-polar f θ-min θ-max θ-samples ρ-min ρ-max ρ-samples)
-  (for*/list ([θ  (in-list (linear-seq θ-min θ-max θ-samples))]
-              [ρ  (in-list (linear-seq ρ-min ρ-max ρ-samples))])
-    (3d-polar->3d-cartesian θ ρ (f θ ρ))))
+(defproc (make-2d-function->sampler [transform-x-thnk (-> axis-transform/c)]
+                                    [transform-y-thnk (-> axis-transform/c)]
+                                    ) ((real? real? . -> . real?) . -> . 2d-sampler/c)
+  (λ (f)
+    (define memo (make-hash))
+    (λ (x-min x-max x-samples y-min y-max y-samples)
+      (define tx (transform-x-thnk))
+      (define ty (transform-y-thnk))
+      (hash-ref! memo (vector x-min x-max x-samples tx y-min y-max y-samples ty)
+                 (λ ()
+                   (define xs (nonlinear-seq x-min x-max x-samples tx))
+                   (define ys (nonlinear-seq y-min y-max y-samples ty))
+                   (list xs ys (for/vector #:length y-samples ([y  (in-list ys)])
+                                 (for/vector #:length x-samples ([x  (in-list xs)])
+                                   (f x y)))))))))
 
-(define ((make-function->sampler transform-thnk) f)
-  (define memo (make-hash))
-  (λ (x-min x-max x-samples)
-    (define tx (transform-thnk))
-    (hash-ref! memo (vector x-min x-max x-samples tx)
-               (λ ()
-                 (define xs (nonlinear-seq x-min x-max x-samples tx))
-                 (list xs (map* f xs))))))
+(defproc (make-3d-function->sampler [transform-x-thnk (-> axis-transform/c)]
+                                    [transform-y-thnk (-> axis-transform/c)]
+                                    [transform-z-thnk (-> axis-transform/c)]
+                                    ) ((real? real? real? . -> . real?) . -> . 3d-sampler/c)
+  (λ (f)
+    (define memo (make-hash))
+    (λ (x-min x-max x-samples y-min y-max y-samples z-min z-max z-samples)
+      (define tx (transform-x-thnk))
+      (define ty (transform-y-thnk))
+      (define tz (transform-z-thnk))
+      (hash-ref! memo (vector x-min x-max x-samples tx
+                              y-min y-max y-samples ty
+                              z-min z-max z-samples tz)
+                 (λ ()
+                   (define xs (nonlinear-seq x-min x-max x-samples tx))
+                   (define ys (nonlinear-seq y-min y-max y-samples ty))
+                   (define zs (nonlinear-seq z-min z-max z-samples tz))
+                   (list xs ys zs (for/vector #:length z-samples ([z  (in-list zs)])
+                                    (for/vector #:length y-samples ([y  (in-list ys)])
+                                      (for/vector #:length x-samples ([x  (in-list xs)])
+                                        (f x y z))))))))))
 
-(define ((make-2d-function->sampler transform-x-thnk transform-y-thnk) f)
-  (define memo (make-hash))
-  (λ (x-min x-max x-samples y-min y-max y-samples)
-    (define tx (transform-x-thnk))
-    (define ty (transform-y-thnk))
-    (hash-ref! memo (vector x-min x-max x-samples tx y-min y-max y-samples ty)
-               (λ ()
-                 (define xs (nonlinear-seq x-min x-max x-samples tx))
-                 (define ys (nonlinear-seq y-min y-max y-samples ty))
-                 (list xs ys (for/vector #:length y-samples ([y  (in-list ys)])
-                               (for/vector #:length x-samples ([x  (in-list xs)])
-                                 (f x y))))))))
-
-(define ((make-3d-function->sampler transform-x-thnk transform-y-thnk transform-z-thnk) f)
-  (define memo (make-hash))
-  (λ (x-min x-max x-samples y-min y-max y-samples z-min z-max z-samples)
-    (define tx (transform-x-thnk))
-    (define ty (transform-y-thnk))
-    (define tz (transform-z-thnk))
-    (hash-ref! memo (vector x-min x-max x-samples tx
-                            y-min y-max y-samples ty
-                            z-min z-max z-samples tz)
-               (λ ()
-                 (define xs (nonlinear-seq x-min x-max x-samples tx))
-                 (define ys (nonlinear-seq y-min y-max y-samples ty))
-                 (define zs (nonlinear-seq z-min z-max z-samples tz))
-                 (list xs ys zs (for/vector #:length z-samples ([z  (in-list zs)])
-                                  (for/vector #:length y-samples ([y  (in-list ys)])
-                                    (for/vector #:length x-samples ([x  (in-list xs)])
-                                      (f x y z)))))))))
-
-(define (2d-sample->list zss)
+(defproc (2d-sample->list [zss (vectorof (vectorof real?))]) (listof real?)
   (for*/list ([zs  (in-vector zss)]
               [z   (in-vector zs)])
     z))
 
-(define (3d-sample->list dsss)
+(defproc (3d-sample->list [dsss (vectorof (vectorof (vectorof real?)))]) (listof real?)
   (for*/list ([dss  (in-vector dsss)]
               [ds   (in-vector dss)]
               [d    (in-vector ds)])
diff --git a/collects/plot/custom.rkt b/collects/plot/common/samplers.rkt
similarity index 56%
rename from collects/plot/custom.rkt
rename to collects/plot/common/samplers.rkt
index 56cfcddb86..515320d911 100644
--- a/collects/plot/custom.rkt
+++ b/collects/plot/common/samplers.rkt
@@ -1,48 +1,26 @@
 #lang racket/base
 
-(require racket/contract racket/match racket/list
-         "common/contract-doc.rkt"
-         "common/format.rkt"
-         ;"common/math.rkt"
-         ;"common/contract.rkt"
-         ;"common/format.rkt"
-         ;"common/plot-element.rkt"
-         ;"common/area.rkt"
-         ;"common/axis-transform.rkt"
-         ;"common/utils.rkt"
-         ;"common/marching-squares.rkt"
-         ;"common/marching-cubes.rkt"
-         ;"plot2d/clip.rkt"
-         ;"plot3d/clip.rkt"
-         )
+;; Functions that sample from functions, and functions that create memoized samplers.
 
-(require "common/ticks.rkt")
-(provide (all-from-out "common/ticks.rkt"))
-
-(require "common/parameters.rkt")
-(provide (all-from-out "common/parameters.rkt"))
-
-(require "common/sample.rkt")
-(provide (all-from-out "common/sample.rkt"))
-
-(require "common/draw.rkt")
-(provide maybe-apply/list)
-
-(require "common/legend.rkt")
-(provide (all-from-out "common/legend.rkt"))
-
-(require "common/plot-element.rkt")
-(provide (all-from-out "common/plot-element.rkt"))
-
-(require "common/marching-squares.rkt")
-(provide (all-from-out "common/marching-squares.rkt"))
+(require racket/match racket/flonum racket/math racket/contract racket/list
+         "parameters.rkt"
+         "sample.rkt"
+         "ticks.rkt"
+         "format.rkt"
+         "contract-doc.rkt")
 
 (provide (all-defined-out))
 
-(define function->sampler (make-function->sampler plot-x-transform))
-(define inverse->sampler (make-function->sampler plot-y-transform))
-(define 2d-function->sampler (make-2d-function->sampler plot-x-transform plot-y-transform))
-(define 3d-function->sampler
+(defthing function->sampler ((real? . -> . real?) . -> . sampler/c)
+  (make-function->sampler plot-x-transform))
+
+(defthing inverse->sampler ((real? . -> . real?) . -> . sampler/c)
+  (make-function->sampler plot-y-transform))
+
+(defthing 2d-function->sampler ((real? real? . -> . real?) . -> . 2d-sampler/c)
+  (make-2d-function->sampler plot-x-transform plot-y-transform))
+
+(defthing 3d-function->sampler ((real? real? real? . -> . real?) . -> . 3d-sampler/c)
   (make-3d-function->sampler plot-x-transform plot-y-transform plot-z-transform))
 
 (defproc (contour-ticks [z-min real?] [z-max real?]
diff --git a/collects/plot/common/ticks.rkt b/collects/plot/common/ticks.rkt
index f900aa08ea..ddd90d70c2 100644
--- a/collects/plot/common/ticks.rkt
+++ b/collects/plot/common/ticks.rkt
@@ -13,31 +13,7 @@
          "date-time.rkt"
          "currency.rkt")
 
-(provide ;(struct-out pre-tick) (struct-out tick) (struct-out ticks)
-         ticks-layout/c ticks-format/c
-         ;; No ticks
-         no-ticks-layout no-ticks
-         ;; Linear ticks
-         linear-ticks-layout linear-ticks-format linear-ticks
-         ;; Log-scale ticks
-         log-ticks-layout log-ticks-format log-ticks
-         ;; Date ticks
-         date-ticks-formats 24h-descending-date-ticks-formats 12h-descending-date-ticks-formats
-         date-ticks-layout date-ticks-format date-ticks
-         ;; Time ticks
-         time-ticks-formats descending-time-ticks-formats
-         time-ticks-layout time-ticks-format time-ticks
-         ;; Bit/byte ticks
-         bit/byte-ticks-format bit/byte-ticks
-         ;; Currency ticks and formats
-         currency-ticks-scales us-currency-scales uk-currency-scales eu-currency-scales
-         currency-ticks-formats us-currency-formats uk-currency-formats eu-currency-formats
-         currency-ticks-layout currency-ticks-format currency-ticks
-         ;; Fractions
-         fraction-ticks-format fraction-ticks
-         ;; Combinators
-         ticks-mimic ticks-scale ticks-add linear-scale
-         )
+(provide (all-defined-out))
 
 (struct pre-tick (value major?) #:transparent)
 (struct tick pre-tick (label) #:transparent)
@@ -56,10 +32,6 @@
 (defcontract ticks-format/c
   (real? real? (listof pre-tick?) . -> . (listof string?)))
 
-(provide (contract-out (struct pre-tick ([value real?] [major? boolean?]))
-                       (struct (tick pre-tick) ([value real?] [major? boolean?] [label string?]))
-                       (struct ticks ([layout ticks-layout/c] [format ticks-format/c]))))
-
 ;; ===================================================================================================
 ;; Helpers
 
@@ -223,39 +195,43 @@
          (break step)))
      #f)))
 
-(define (count-unchanging-fields formatter fmt-list xs)
+(define (count-changing-fields formatter fmt-list xs)
   (let ([fmt-list  (filter symbol? fmt-list)])
     (define formatted-dates (for/list ([x  (in-list xs)])
                               (apply-formatter formatter fmt-list x)))
-    (count equal?* (transpose formatted-dates))))
+    (count (λ (fields) (not (apply equal?* fields)))
+           (transpose formatted-dates))))
 
+;; Find the shortest format string that has the maximum number of changing fields
 (define (choose-format-list formatter fmt-lists xs)
-  (let ([fmt-lists  (sort fmt-lists >
+  (let ([fmt-lists  (sort fmt-lists <
                           #:key (λ (fmt-list) (count symbol? fmt-list))
                           #:cache-keys? #t)])
-    (argmin (λ (fmt-list) (count-unchanging-fields formatter fmt-list xs))
+    (argmax (λ (fmt-list) (count-changing-fields formatter fmt-list xs))
             fmt-lists)))
 
 ;; ===================================================================================================
 ;; Date ticks
 
 (define 12h-descending-date-ticks-formats
-  '("~Y-~m-~d ~I:~M:~f~p"
-    "~Y-~m-~d ~I:~M~p"
-    "~Y-~m-~d ~I~p"
+  '("~Y-~m-~d ~I:~M:~f ~p"
+    "~Y-~m-~d ~I:~M ~p"
+    "~Y-~m-~d ~I ~p"
     "~Y-~m-~d"
     "~Y-~m"
     "~Y"
     
-    "~m-~d ~I:~M:~f~p"
-    "~m-~d ~I:~M~p"
-    "~m-~d ~I~p"
+    "~m-~d ~I:~M:~f ~p"
+    "~m-~d ~I:~M ~p"
+    "~m-~d ~I ~p"
     "~m-~d"
     
-    "~I:~M:~f~p"
-    "~I:~M~p"
+    "~I:~M:~f ~p"
+    "~I:~M ~p"
+    "~I ~p"
     
     "~M:~fs"
+    "~Mm"
     
     "~fs"))
 
@@ -274,8 +250,10 @@
     
     "~H:~M:~f"
     "~H:~M"
+    "~Hh"
     
     "~M:~fs"
+    "~Mm"
     
     "~fs"))
 
@@ -375,7 +353,7 @@
     "~H:~M"
     "~Hh"
     
-    "~M:~f"
+    "~M:~fs"
     "~Mm"
     
     "~fs"))
diff --git a/collects/plot/compat.rkt b/collects/plot/compat.rkt
index 36f9b42d07..f4979e3889 100644
--- a/collects/plot/compat.rkt
+++ b/collects/plot/compat.rkt
@@ -3,6 +3,7 @@
 ;; A compatibility module for the old 'plot'.
 
 (require racket/contract racket/class racket/snip racket/draw racket/vector
+         unstable/latent-contract
          ;; Plotting
          "common/contract.rkt"
          "common/contract-doc.rkt"
@@ -22,12 +23,14 @@
          ;; Miscellaneous
          "deprecated/math.rkt")
 
-(provide mix plot-color?
-         plot plot3d
-         points vector-field error-bars
-         line
-         contour shade
-         surface
+(provide mix
+         (activate-contract-out plot-color?
+                                plot plot3d
+                                points vector-field error-bars
+                                line
+                                contour shade
+                                surface)
+         (only-doc-out (all-defined-out))
          ;; Curve fitting
          (rename-out [fit-int fit])
          (struct-out fit-result)
@@ -81,7 +84,8 @@
                  [new.plot-background  bgcolor])
     (define bm (make-bitmap (ceiling width) (ceiling height)))
     (define dc (make-object bitmap-dc% bm))
-    (define area (make-object 2d-plot-area% x-ticks y-ticks x-min x-max y-min y-max
+    (define area (make-object 2d-plot-area% x-ticks x-ticks y-ticks y-ticks
+                   x-min x-max y-min y-max
                    dc 0 0 width height))
     
     (send area start-plot)
@@ -124,7 +128,8 @@
     (define bm (make-bitmap (ceiling width) (ceiling height)))
     (define dc (make-object bitmap-dc% bm))
     (define area
-      (make-object 3d-plot-area% x-ticks y-ticks z-ticks x-min x-max y-min y-max z-min z-max
+      (make-object 3d-plot-area% x-ticks x-ticks y-ticks y-ticks z-ticks z-ticks
+        x-min x-max y-min y-max z-min z-max
         dc 0 0 width height))
     
     (send area start-plot)
diff --git a/collects/plot/contracted/axis-transform.rkt b/collects/plot/contracted/axis-transform.rkt
new file mode 100644
index 0000000000..a18ed776b2
--- /dev/null
+++ b/collects/plot/contracted/axis-transform.rkt
@@ -0,0 +1,20 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract)
+
+(require "../common/axis-transform.rkt")
+(provide (contract-out (struct invertible-function ([f (real? . -> . real?)]
+                                                    [g (real? . -> . real?)])))
+         (activate-contract-out id-function
+                                axis-transform/c
+                                id-transform
+                                apply-transform
+                                make-axis-transform
+                                axis-transform-compose
+                                axis-transform-append
+                                axis-transform-bound
+                                log-transform
+                                cbrt-transform
+                                hand-drawn-transform
+                                stretch-transform
+                                collapse-transform))
diff --git a/collects/plot/contracted/date-time.rkt b/collects/plot/contracted/date-time.rkt
new file mode 100644
index 0000000000..a605d0364b
--- /dev/null
+++ b/collects/plot/contracted/date-time.rkt
@@ -0,0 +1,11 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract)
+
+(require "../common/date-time.rkt")
+(provide (contract-out (struct plot-time ([second (and/c (>=/c 0) (</c 60))]
+                                          [minute (integer-in 0 59)]
+                                          [hour (integer-in 0 23)]
+                                          [day exact-integer?])))
+         (activate-contract-out plot-time->seconds seconds->plot-time
+                                datetime->real))
diff --git a/collects/plot/contracted/draw.rkt b/collects/plot/contracted/draw.rkt
new file mode 100644
index 0000000000..8d7e11610a
--- /dev/null
+++ b/collects/plot/contracted/draw.rkt
@@ -0,0 +1,9 @@
+#lang racket/base
+
+(require unstable/latent-contract)
+
+(require "../common/draw.rkt")
+(provide (activate-contract-out ->color ->pen-color ->brush-color ->pen-style ->brush-style
+                                color-seq color-seq*
+                                alpha-expt
+                                maybe-apply/list))
diff --git a/collects/plot/contracted/format.rkt b/collects/plot/contracted/format.rkt
new file mode 100644
index 0000000000..d43e5bb206
--- /dev/null
+++ b/collects/plot/contracted/format.rkt
@@ -0,0 +1,11 @@
+#lang racket/base
+
+(require unstable/latent-contract)
+
+(require "../common/format.rkt")
+(provide (activate-contract-out
+          integer->superscript
+          digits-for-range
+          real->decimal-string* real->string/trunc
+          real->plot-label ->plot-label
+          parse-format-string apply-formatter))
diff --git a/collects/plot/contracted/legend.rkt b/collects/plot/contracted/legend.rkt
new file mode 100644
index 0000000000..e981f3fbf7
--- /dev/null
+++ b/collects/plot/contracted/legend.rkt
@@ -0,0 +1,16 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract racket/class)
+
+(require "../common/legend.rkt"
+         "../common/area.rkt")
+(provide (contract-out
+          (struct legend-entry ([label string?]
+                                [draw ((is-a?/c plot-area%) real? real? real? real? . -> . void?)])))
+         (activate-contract-out
+          line-legend-entry line-legend-entries
+          rectangle-legend-entry rectangle-legend-entries
+          interval-legend-entry interval-legend-entries
+          contour-intervals-legend-entries
+          point-legend-entry
+          vector-field-legend-entry))
diff --git a/collects/plot/contracted/math.rkt b/collects/plot/contracted/math.rkt
new file mode 100644
index 0000000000..777898c408
--- /dev/null
+++ b/collects/plot/contracted/math.rkt
@@ -0,0 +1,33 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract)
+
+(require "../common/math.rkt")
+(provide equal?*
+         ;; Flonums
+         nan? infinite? special?
+         flblend flatan2 flsum flmodulo fldistance
+         ;; Reals
+         regular?
+         min* max* degrees->radians radians->degrees blend atan2 sum real-modulo distance
+         floor-log/base ceiling-log/base
+         polar->cartesian 3d-polar->3d-cartesian
+         ;; Vectors
+         vcross v+ v- vneg v* v/ vmag^2 vmag vnormalize vdot vregular? v= vcenter)
+
+;; Intervals
+(provide (contract-out (struct ivl ([min (or/c real? #f)] [max (or/c real? #f)]))
+                       [ivl-meet  (->* () () #:rest (listof ivl?) ivl?)]
+                       [ivl-join  (->* () () #:rest (listof ivl?) ivl?)])
+         empty-ivl unknown-ivl
+         (activate-contract-out
+          ivl-empty? ivl-known? ivl-regular? ivl-singular? ivl-zero-length?
+          ivl-inexact->exact ivl-contains? bounds->intervals))
+
+;; Rectangles
+(provide (contract-out [rect-meet (->* () () #:rest (listof (vectorof ivl?)) (vectorof ivl?))]
+                       [rect-join (->* () () #:rest (listof (vectorof ivl?)) (vectorof ivl?))])
+         (activate-contract-out
+          empty-rect unknown-rect bounding-rect
+          rect-empty? rect-known? rect-regular? rect-zero-area? rect-singular?
+          rect-inexact->exact rect-contains?))
diff --git a/collects/plot/contracted/parameters.rkt b/collects/plot/contracted/parameters.rkt
new file mode 100644
index 0000000000..eea24e58bd
--- /dev/null
+++ b/collects/plot/contracted/parameters.rkt
@@ -0,0 +1,79 @@
+#lang racket/base
+
+(require unstable/latent-contract)
+
+(require "../common/parameters.rkt")
+(provide
+ (activate-contract-out
+  plot-deprecation-warnings?
+  ;; General plot parameters
+  plot-x-axis? plot-y-axis? plot-z-axis?
+  plot-x-far-axis? plot-y-far-axis? plot-z-far-axis?
+  plot-x-max-ticks plot-y-max-ticks plot-z-max-ticks plot-d-max-ticks plot-r-max-ticks
+  plot-x-far-max-ticks plot-y-far-max-ticks plot-z-far-max-ticks
+  plot-width plot-height
+  plot-foreground plot-foreground-alpha
+  plot-background plot-background-alpha
+  plot-line-width plot-tick-size
+  plot-font-size plot-font-family
+  plot-legend-anchor plot-legend-box-alpha
+  plot-decorations?
+  plot-animating?
+  plot3d-samples
+  plot3d-angle plot3d-altitude
+  plot3d-ambient-light plot3d-diffuse-light? plot3d-specular-light?
+  plot-new-window? plot-jpeg-quality plot-ps/pdf-interactive?
+  plot-title
+  plot-x-label plot-y-label plot-z-label
+  plot-x-far-label plot-y-far-label plot-z-far-label
+  plot-x-transform plot-x-ticks plot-x-far-ticks
+  plot-y-transform plot-y-ticks plot-y-far-ticks
+  plot-z-transform plot-z-ticks plot-z-far-ticks
+  plot-d-transform plot-d-ticks
+  plot-r-transform plot-r-ticks
+  ;; Renderer parameters
+  line-samples line-color line-width line-style line-alpha
+  interval-color interval-style
+  interval-line1-color interval-line1-width interval-line1-style
+  interval-line2-color interval-line2-width interval-line2-style
+  interval-alpha
+  point-sym point-color point-size point-line-width point-alpha
+  vector-field-samples
+  vector-field-color vector-field-line-width vector-field-line-style
+  vector-field-scale
+  vector-field-alpha
+  error-bar-width error-bar-color error-bar-line-width error-bar-line-style error-bar-alpha
+  contour-samples contour-levels contour-colors contour-widths contour-styles contour-alphas
+  contour-interval-colors contour-interval-styles contour-interval-alphas
+  rectangle-color rectangle-style
+  rectangle-line-color rectangle-line-width rectangle-line-style
+  rectangle-alpha
+  discrete-histogram-gap
+  rectangle3d-line-width
+  x-axis-ticks? y-axis-ticks? z-axis-ticks?
+  x-axis-labels? y-axis-labels? z-axis-labels?
+  x-axis-far? y-axis-far? z-axis-far?
+  x-axis-alpha y-axis-alpha z-axis-alpha
+  polar-axes-number polar-axes-ticks? polar-axes-labels? polar-axes-alpha
+  label-anchor label-angle label-alpha label-point-size
+  surface-color surface-style surface-line-color surface-line-width surface-line-style surface-alpha
+  contour-interval-line-colors contour-interval-line-widths contour-interval-line-styles
+  isosurface-levels
+  isosurface-colors isosurface-line-colors isosurface-line-widths isosurface-line-styles
+  isosurface-alphas
+  ;; Functions
+  pen-gap
+  animated-samples
+  default-x-ticks default-y-ticks default-z-ticks default-d-ticks default-r-ticks
+  default-x-far-ticks default-y-far-ticks default-z-far-ticks
+  default-contour-colors default-contour-fill-colors
+  default-isosurface-colors default-isosurface-line-colors)
+ ;; Parameter groups
+ plot-parameters
+ plot-axes?
+ plot-max-ticks
+ plot-appearance
+ plot3d-appearance
+ plot-output
+ plot-labels
+ plot-axes plot-x-axis plot-y-axis plot-z-axis)
diff --git a/collects/plot/contracted/plot-element.rkt b/collects/plot/contracted/plot-element.rkt
new file mode 100644
index 0000000000..271ccbd3fd
--- /dev/null
+++ b/collects/plot/contracted/plot-element.rkt
@@ -0,0 +1,36 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract racket/class)
+
+(require "../common/contract.rkt"
+         "../common/plot-element.rkt"
+         "../common/math.rkt"
+         "../common/legend.rkt"
+         "../plot2d/area.rkt"
+         "../plot3d/area.rkt")
+
+(provide
+ (contract-out
+  (struct plot-element
+    ([bounds-rect  (or/c (vectorof ivl?) #f)]
+     [bounds-fun   (or/c bounds-fun/c #f)]
+     [ticks-fun    (or/c ticks-fun/c #f)]))
+  (struct (non-renderer plot-element)
+    ([bounds-rect  (or/c (vectorof ivl?) #f)]
+     [bounds-fun   (or/c bounds-fun/c #f)]
+     [ticks-fun    (or/c ticks-fun/c #f)]))
+  (struct (renderer2d plot-element)
+    ([bounds-rect  (or/c (vectorof ivl?) #f)]
+     [bounds-fun   (or/c bounds-fun/c #f)]
+     [ticks-fun    (or/c ticks-fun/c #f)]
+     [render-proc  (or/c ((is-a?/c 2d-plot-area%) . -> . (treeof legend-entry?)) #f)]))
+  (struct (renderer3d plot-element)
+    ([bounds-rect  (or/c (vectorof ivl?) #f)]
+     [bounds-fun   (or/c bounds-fun/c #f)]
+     [ticks-fun    (or/c ticks-fun/c #f)]
+     [render-proc  (or/c ((is-a?/c 3d-plot-area%) . -> . (treeof legend-entry?)) #f)])))
+ bounds-fun/c ticks-fun/c
+ (activate-contract-out default-ticks-fun
+                        function-bounds-fun function-interval-bounds-fun
+                        inverse-bounds-fun inverse-interval-bounds-fun
+                        surface3d-bounds-fun))
diff --git a/collects/plot/contracted/sample.rkt b/collects/plot/contracted/sample.rkt
new file mode 100644
index 0000000000..d61d826af5
--- /dev/null
+++ b/collects/plot/contracted/sample.rkt
@@ -0,0 +1,16 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract)
+
+(require "../common/sample.rkt")
+(provide (activate-contract-out build-linear-seq linear-seq linear-seq* nonlinear-seq
+                                sample/c sampler/c
+                                2d-sample/c 2d-sampler/c
+                                3d-sample/c 3d-sampler/c
+                                make-function->sampler
+                                make-2d-function->sampler
+                                make-3d-function->sampler
+                                2d-sample->list 3d-sample->list)
+         (contract-out (struct mapped-function ([f (any/c . -> . any/c)]
+                                                [fmap ((listof any/c) . -> . (listof any/c))])))
+         map*)
diff --git a/collects/plot/contracted/samplers.rkt b/collects/plot/contracted/samplers.rkt
new file mode 100644
index 0000000000..9a650652b8
--- /dev/null
+++ b/collects/plot/contracted/samplers.rkt
@@ -0,0 +1,10 @@
+#lang racket/base
+
+(require unstable/latent-contract)
+
+(require "../common/samplers.rkt")
+(provide (activate-contract-out contour-ticks
+                                function->sampler
+                                inverse->sampler
+                                2d-function->sampler
+                                3d-function->sampler))
diff --git a/collects/plot/contracted/ticks.rkt b/collects/plot/contracted/ticks.rkt
new file mode 100644
index 0000000000..3a8fb658ce
--- /dev/null
+++ b/collects/plot/contracted/ticks.rkt
@@ -0,0 +1,24 @@
+#lang racket/base
+
+(require racket/contract unstable/latent-contract)
+
+(require "../common/ticks.rkt")
+(provide
+ (contract-out (struct pre-tick ([value real?] [major? boolean?]))
+               (struct (tick pre-tick) ([value real?] [major? boolean?] [label string?]))
+               (struct ticks ([layout ticks-layout/c] [format ticks-format/c])))
+ 24h-descending-date-ticks-formats 12h-descending-date-ticks-formats
+ descending-time-ticks-formats
+ us-currency-scales uk-currency-scales eu-currency-scales
+ us-currency-formats uk-currency-formats eu-currency-formats
+ ticks-layout/c ticks-format/c
+ (activate-contract-out ticks-mimic ticks-scale ticks-add linear-scale
+                        no-ticks-layout no-ticks
+                        linear-ticks-layout linear-ticks-format linear-ticks
+                        log-ticks-layout log-ticks-format log-ticks
+                        date-ticks-formats date-ticks-layout date-ticks-format date-ticks
+                        time-ticks-formats time-ticks-layout time-ticks-format time-ticks
+                        bit/byte-ticks-format bit/byte-ticks
+                        currency-ticks-scales currency-ticks-formats
+                        currency-ticks-layout currency-ticks-format currency-ticks
+                        fraction-ticks-format fraction-ticks))
diff --git a/collects/plot/deprecated.rkt b/collects/plot/deprecated/deprecated.rkt
similarity index 80%
rename from collects/plot/deprecated.rkt
rename to collects/plot/deprecated/deprecated.rkt
index df56b996a9..a2e1bef88c 100644
--- a/collects/plot/deprecated.rkt
+++ b/collects/plot/deprecated/deprecated.rkt
@@ -1,18 +1,11 @@
 #lang racket/base
 
-(require racket/contract racket/match racket/class racket/snip racket/draw racket/string
-         ;; Plotting
-         "common/deprecation-warning.rkt"
-         "common/contract.rkt"
-         "common/contract-doc.rkt"
-         "common/plot-element.rkt"
-         "plot2d/line.rkt"
-         "plot2d/contour.rkt"
-         "plot3d/surface.rkt"
-         "deprecated/renderers.rkt"
-         "utils.rkt")
+(require racket/contract plot/utils
+         "../common/deprecation-warning.rkt"
+         "../common/contract-doc.rkt"
+         "renderers.rkt")
 
-(provide mix line contour shade surface)
+(provide (all-defined-out))
 
 (define (mix . renderers)
   (deprecation-warning "mix" "list")
diff --git a/collects/plot/deprecated/renderers.rkt b/collects/plot/deprecated/renderers.rkt
index 1357883673..c81c46825b 100644
--- a/collects/plot/deprecated/renderers.rkt
+++ b/collects/plot/deprecated/renderers.rkt
@@ -2,11 +2,10 @@
 
 ;; Functions that create renderers for backward-compatible functions 'line', 'contour', etc.
 
-(require racket/match
+(require racket/match plot/utils
          "../plot2d/line.rkt"
          "../plot2d/contour.rkt"
-         "../plot3d/surface.rkt"
-         "../utils.rkt")
+         "../plot3d/surface.rkt")
 
 (provide line-renderer
          contour-renderer
diff --git a/collects/plot/doc.rkt b/collects/plot/doc.rkt
new file mode 100644
index 0000000000..44cce52ef5
--- /dev/null
+++ b/collects/plot/doc.rkt
@@ -0,0 +1,79 @@
+#lang racket/base
+
+(require "common/contract-doc.rkt")
+
+;; ===================================================================================================
+;; Common exports
+
+(require "common/parameters.rkt"
+         "common/contract.rkt"
+         "common/axis-transform.rkt"
+         "common/ticks.rkt"
+         "common/math.rkt"
+         "common/plot-element.rkt"
+         "common/non-renderer.rkt"
+         "common/format.rkt"
+         "common/sample.rkt"
+         "common/draw.rkt"
+         "common/date-time.rkt")
+
+(provide (only-doc-out
+          (combine-out (all-from-out "common/parameters.rkt")
+                       (all-from-out "common/contract.rkt")
+                       (all-from-out "common/axis-transform.rkt")
+                       (all-from-out "common/ticks.rkt")
+                       (all-from-out "common/math.rkt")
+                       (all-from-out "common/plot-element.rkt")
+                       (all-from-out "common/non-renderer.rkt")
+                       (all-from-out "common/format.rkt")
+                       (all-from-out "common/sample.rkt")
+                       (all-from-out "common/draw.rkt")
+                       (all-from-out "common/date-time.rkt"))))
+
+;; ===================================================================================================
+;; 2D exports
+
+(require "plot2d/plot.rkt"
+         "plot2d/point.rkt"
+         "plot2d/line.rkt"
+         "plot2d/interval.rkt"
+         "plot2d/contour.rkt"
+         "plot2d/rectangle.rkt"
+         "plot2d/decoration.rkt"
+         "plot2d/kde.rkt")
+
+(provide (only-doc-out
+          (combine-out (all-from-out "plot2d/plot.rkt")
+                       (all-from-out "plot2d/point.rkt")
+                       (all-from-out "plot2d/line.rkt")
+                       (all-from-out "plot2d/interval.rkt")
+                       (all-from-out "plot2d/contour.rkt")
+                       (all-from-out "plot2d/rectangle.rkt")
+                       (all-from-out "plot2d/decoration.rkt")
+                       (all-from-out "plot2d/kde.rkt"))))
+
+;; ===================================================================================================
+;; 3D exports
+
+(require "plot3d/plot.rkt"
+         "plot3d/surface.rkt"
+         "plot3d/contour.rkt"
+         "plot3d/line.rkt"
+         "plot3d/point.rkt"
+         "plot3d/isosurface.rkt"
+         "plot3d/rectangle.rkt")
+
+(provide (only-doc-out
+          (combine-out (all-from-out "plot3d/plot.rkt")
+                       (all-from-out "plot3d/surface.rkt")
+                       (all-from-out "plot3d/contour.rkt")
+                       (all-from-out "plot3d/line.rkt")
+                       (all-from-out "plot3d/point.rkt")
+                       (all-from-out "plot3d/isosurface.rkt")
+                       (all-from-out "plot3d/rectangle.rkt"))))
+
+;; ===================================================================================================
+;; Deprecated functions
+
+(require "deprecated/deprecated.rkt")
+(provide (only-doc-out (all-from-out "deprecated/deprecated.rkt")))
diff --git a/collects/plot/main.rkt b/collects/plot/main.rkt
index 4cd59cc499..c1d721b0f2 100644
--- a/collects/plot/main.rkt
+++ b/collects/plot/main.rkt
@@ -1,73 +1,90 @@
 #lang racket/base
 
-(require racket/contract)
+(require racket/contract unstable/latent-contract)
 
 ;; ===================================================================================================
-;; Common exports
+;; General exports
 
-(require "common/parameters.rkt"
-         "common/contract.rkt")
+(require "contracted/parameters.rkt")
+(provide (all-from-out "contracted/parameters.rkt"))
 
-(provide (all-from-out "common/parameters.rkt")
-         (all-from-out "common/contract.rkt"))
-
-(require "common/axis-transform.rkt")
-(provide (all-from-out "common/axis-transform.rkt"))
-
-(require "common/ticks.rkt")
-(provide (all-from-out "common/ticks.rkt"))
-
-(require "common/math.rkt")
+(require "contracted/math.rkt")
 (provide (struct-out ivl))
 
-(require "common/plot-element.rkt")
-(provide plot-element? non-renderer? renderer2d? renderer3d?)
+(require "contracted/axis-transform.rkt")
+(provide axis-transform-compose axis-transform-append axis-transform-bound
+         id-transform log-transform cbrt-transform hand-drawn-transform
+         stretch-transform collapse-transform)
+
+(require "contracted/ticks.rkt")
+(provide (all-from-out "contracted/ticks.rkt"))
+
+(require "contracted/date-time.rkt")
+(provide (struct-out plot-time)
+         plot-time->seconds seconds->plot-time
+         datetime->real)
 
 (require "common/non-renderer.rkt")
-(provide (all-from-out "common/non-renderer.rkt"))
+(provide (activate-contract-out x-ticks y-ticks z-ticks invisible-box invisible-box3d))
 
 ;; ===================================================================================================
 ;; 2D exports
 
-(require "plot2d/plot.rkt"
-         "plot2d/point.rkt"
-         "plot2d/line.rkt"
-         "plot2d/interval.rkt"
-         "plot2d/contour.rkt"
-         "plot2d/rectangle.rkt"
-         "plot2d/decoration.rkt"
-         "plot2d/kde.rkt")
+(require "plot2d/plot.rkt")
+(provide (activate-contract-out plot/dc plot plot-bitmap plot-pict plot-snip plot-frame plot-file))
 
-(provide (all-from-out "plot2d/plot.rkt")
-         (all-from-out "plot2d/point.rkt")
-         (all-from-out "plot2d/line.rkt")
-         (all-from-out "plot2d/interval.rkt")
-         (all-from-out "plot2d/contour.rkt")
-         (all-from-out "plot2d/rectangle.rkt")
-         (all-from-out "plot2d/decoration.rkt")
-         density)
+(require "plot2d/point.rkt")
+(provide (activate-contract-out points vector-field error-bars))
+
+(require "plot2d/line.rkt")
+(provide (activate-contract-out lines parametric polar function inverse))
+
+(require "plot2d/interval.rkt")
+(provide (activate-contract-out
+          lines-interval parametric-interval polar-interval function-interval inverse-interval))
+
+(require "plot2d/contour.rkt")
+(provide (activate-contract-out contours contour-intervals))
+
+(require "plot2d/rectangle.rkt")
+(provide (activate-contract-out rectangles area-histogram discrete-histogram))
+
+(require "plot2d/decoration.rkt")
+(provide (activate-contract-out
+          x-axis y-axis axes polar-axes
+          x-tick-lines y-tick-lines tick-grid
+          point-label parametric-label polar-label function-label inverse-label))
+
+(require "plot2d/kde.rkt")
+(provide (activate-contract-out density))
 
 ;; ===================================================================================================
 ;; 3D exports
 
-(require "plot3d/plot.rkt"
-         "plot3d/surface.rkt"
-         "plot3d/contour.rkt"
-         "plot3d/line.rkt"
-         "plot3d/point.rkt"
-         "plot3d/isosurface.rkt"
-         "plot3d/rectangle.rkt")
+(require "plot3d/plot.rkt")
+(provide (activate-contract-out
+          plot3d/dc plot3d plot3d-bitmap plot3d-pict plot3d-snip plot3d-frame plot3d-file))
 
-(provide (all-from-out "plot3d/plot.rkt")
-         (all-from-out "plot3d/surface.rkt")
-         (all-from-out "plot3d/contour.rkt")
-         (all-from-out "plot3d/line.rkt")
-         (all-from-out "plot3d/point.rkt")
-         (all-from-out "plot3d/isosurface.rkt")
-         (all-from-out "plot3d/rectangle.rkt"))
+(require "plot3d/surface.rkt")
+(provide (activate-contract-out surface3d))
+
+(require "plot3d/contour.rkt")
+(provide (activate-contract-out contours3d contour-intervals3d))
+
+(require "plot3d/line.rkt")
+(provide (activate-contract-out lines3d parametric3d))
+
+(require "plot3d/point.rkt")
+(provide (activate-contract-out points3d))
+
+(require "plot3d/isosurface.rkt")
+(provide (activate-contract-out isosurface3d isosurfaces3d polar3d))
+
+(require "plot3d/rectangle.rkt")
+(provide (activate-contract-out rectangles3d discrete-histogram3d))
 
 ;; ===================================================================================================
 ;; Deprecated functions
 
-(require "deprecated.rkt")
-(provide (all-from-out "deprecated.rkt"))
+(require "deprecated/deprecated.rkt")
+(provide mix (activate-contract-out line contour shade surface))
diff --git a/collects/plot/plot2d/area.rkt b/collects/plot/plot2d/area.rkt
index 766f3ac3b4..337b221ca9 100644
--- a/collects/plot/plot2d/area.rkt
+++ b/collects/plot/plot2d/area.rkt
@@ -200,7 +200,8 @@
       (define offset (vector 0 (+ max-x-tick-offset
                                   max-x-tick-label-height
                                   (* 1/2 char-height))))
-      (list (plot-x-label) (v+ (view->dc (vector (* 1/2 (+ x-min x-max)) y-min)) offset) 'top))
+      (list (plot-x-label) (v+ (view->dc (vector (* 1/2 (+ x-min x-max)) y-min)) offset)
+            'top))
     
     (define (get-y-label-params)
       (define offset (vector (+ max-y-tick-offset
@@ -214,7 +215,8 @@
       (define offset (vector 0 (+ max-x-far-tick-offset
                                   max-x-far-tick-label-height
                                   (* 1/2 char-height))))
-      (list (plot-x-far-label) (v- (view->dc (vector (* 1/2 (+ x-min x-max)) y-max)) offset) 'bottom))
+      (list (plot-x-far-label) (v- (view->dc (vector (* 1/2 (+ x-min x-max)) y-max)) offset)
+            'bottom))
     
     (define (get-y-far-label-params)
       (define offset (vector (+ max-y-far-tick-offset
diff --git a/collects/plot/plot2d/contour.rkt b/collects/plot/plot2d/contour.rkt
index 4d46b74d63..a5b57b77b2 100644
--- a/collects/plot/plot2d/contour.rkt
+++ b/collects/plot/plot2d/contour.rkt
@@ -3,10 +3,10 @@
 ;; Renderers for contour lines and contour intervals
 
 (require racket/contract racket/class racket/match racket/list racket/flonum racket/vector
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide contours contour-intervals)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Contour lines
diff --git a/collects/plot/plot2d/decoration.rkt b/collects/plot/plot2d/decoration.rkt
index 8fe06ff762..cde6c98d56 100644
--- a/collects/plot/plot2d/decoration.rkt
+++ b/collects/plot/plot2d/decoration.rkt
@@ -3,7 +3,7 @@
 ;; Renderers for plot decorations: axes, grids, labeled points, etc.
 
 (require racket/contract racket/class racket/match racket/math racket/list
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt"
          "area.rkt"
          "line.rkt"
@@ -12,14 +12,7 @@
          "contour.rkt"
          "clip.rkt")
 
-(provide x-axis y-axis axes
-         polar-axes
-         x-tick-lines y-tick-lines tick-grid
-         point-label
-         parametric-label
-         polar-label
-         function-label
-         inverse-label)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; X and Y axes
@@ -94,9 +87,11 @@
                [#:x-ticks? x-ticks? boolean? (x-axis-ticks?)]
                [#:y-ticks? y-ticks? boolean? (y-axis-ticks?)]
                [#:x-labels? x-labels? boolean? (x-axis-labels?)]
-               [#:y-labels? y-labels? boolean? (y-axis-labels?)]) (listof renderer2d?)
-  (list (x-axis y #:ticks? x-ticks? #:labels? x-labels?)
-        (y-axis x #:ticks? y-ticks? #:labels? y-labels?)))
+               [#:y-labels? y-labels? boolean? (y-axis-labels?)]
+               [#:x-alpha x-alpha (real-in 0 1) (x-axis-alpha)]
+               [#:y-alpha y-alpha (real-in 0 1) (y-axis-alpha)]) (listof renderer2d?)
+  (list (x-axis y #:ticks? x-ticks? #:labels? x-labels? #:alpha x-alpha)
+        (y-axis x #:ticks? y-ticks? #:labels? y-labels? #:alpha y-alpha)))
 
 ;; ===================================================================================================
 ;; Polar axes
@@ -117,63 +112,58 @@
                                                    #:when (and r-min r-max (not (= r-min r-max))))
     (values θ r-min r-max)))
 
-(define (draw-polar-axis-ticks num area)
+(define (draw-polar-axis-ticks num labels? area)
   (define-values (x-min x-max y-min y-max) (send area get-bounds))
-  
   (define-values (θs r-mins r-maxs) (build-polar-axes num x-min x-max y-min y-max
                                                       (* 1/2 (/ (* 2 pi) num))))
-  
   (define corner-rs
     (list (vmag (vector x-min y-min)) (vmag (vector x-min y-max))
           (vmag (vector x-max y-max)) (vmag (vector x-max y-min))))
   (define r-min (if (and (<= x-min 0 x-max) (<= y-min 0 y-max)) 0 (apply min corner-rs)))
   (define r-max (apply max corner-rs))
   (define ts (filter (λ (t) (not (zero? (pre-tick-value t))))
-                     ((linear-ticks) r-min r-max (polar-axes-max-ticks))))
-  
-  (send area set-alpha 1/2)
+                     (default-r-ticks r-min r-max)))
+  ;; Draw the tick lines
   (for ([t  (in-list ts)])
     (match-define (tick r major? label) t)
     (if major? (send area set-major-pen) (send area set-minor-pen 'long-dash))
     (define pts (for/list ([θ  (in-list (linear-seq 0 (* 2 pi) 500))])
                   (vector (* r (cos θ)) (* r (sin θ)))))
     (send area put-lines pts))
-  
-  (when (not (empty? θs))
-    ;; find the longest axis
+  ;; Draw the labels
+  (when (and labels? (not (empty? θs)))
+    ;; Find the longest half-axis, rounded to drown out floating-point error
     (define mag (expt 10 (- (digits-for-range r-min r-max))))
     (match-define (list mθ mr-min mr-max)
-      ;; find the longest, rounded to drown out floating-point error
       (argmax (λ (lst) (* (round (/ (- (third lst) (second lst)) mag)) mag))
               (map list θs r-mins r-maxs)))
-    
-    (send area set-alpha 1)
+    ;; Actually draw the labels
     (for ([t  (in-list ts)])
       (match-define (tick r major? label) t)
       (when (and major? (<= mr-min r mr-max))
         (send area put-text label (vector (* r (cos mθ)) (* r (sin mθ)))
               'center 0 #:outline? #t)))))
 
-(define ((polar-axes-render-proc num ticks?) area)
+(define ((polar-axes-render-proc num ticks? labels? alpha) area)
   (define-values (x-min x-max y-min y-max) (send area get-bounds))
   (define-values (θs r-mins r-maxs) (build-polar-axes num x-min x-max y-min y-max))
-  
   ;; Draw the axes
-  (send area set-alpha 1/2)
+  (send area set-alpha alpha)
   (send area set-major-pen)
   (for ([θ  (in-list θs)] [r-min  (in-list r-mins)] [r-max  (in-list r-maxs)])
     (send area put-line
           (vector (* r-min (cos θ)) (* r-min (sin θ)))
           (vector (* r-max (cos θ)) (* r-max (sin θ)))))
-  
-  (when ticks? (draw-polar-axis-ticks num area))
-  
+  ;; Draw the ticks
+  (when ticks? (draw-polar-axis-ticks num labels? area))
+  ;; No legend
   empty)
 
 (defproc (polar-axes [#:number num exact-positive-integer? (polar-axes-number)]
                      [#:ticks? ticks? boolean? (polar-axes-ticks?)]
-                     ) renderer2d?
-  (renderer2d #f #f #f (polar-axes-render-proc num ticks?)))
+                     [#:labels? labels? boolean? (polar-axes-labels?)]
+                     [#:alpha alpha (real-in 0 1) (polar-axes-alpha)]) renderer2d?
+  (renderer2d #f #f #f (polar-axes-render-proc num ticks? labels? alpha)))
 
 ;; ===================================================================================================
 ;; Grid
diff --git a/collects/plot/plot2d/interval.rkt b/collects/plot/plot2d/interval.rkt
index ab58da4339..3a613f0dfd 100644
--- a/collects/plot/plot2d/interval.rkt
+++ b/collects/plot/plot2d/interval.rkt
@@ -3,10 +3,10 @@
 ;; Renderers for intervals between functions.
 
 (require racket/contract racket/class racket/match racket/math racket/list
-         "../common/contract-doc.rkt"
-         plot/custom plot/utils)
+         plot/utils
+         "../common/contract-doc.rkt")
 
-(provide lines-interval parametric-interval polar-interval function-interval inverse-interval)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Lines, parametric, polar
@@ -82,8 +82,8 @@
           [#:label label (or/c string? #f) #f]
           ) renderer2d?
   (lines-interval
-   (sample-parametric f1 t-min t-max samples)
-   (sample-parametric f2 t-min t-max samples)
+   (map f1 (linear-seq t-min t-max samples))
+   (map f2 (linear-seq t-min t-max samples))
    #:x-min x-min #:x-max x-max #:y-min y-min #:y-max y-max
    #:color color #:style style
    #:line1-color line1-color #:line1-width line1-width #:line1-style line1-style
@@ -107,9 +107,10 @@
           [#:alpha alpha (real-in 0 1) (interval-alpha)]
           [#:label label (or/c string? #f) #f]
           ) renderer2d?
+  (define θs (linear-seq θ-min θ-max samples))
   (lines-interval
-   (sample-polar f1 θ-min θ-max samples)
-   (sample-polar f2 θ-min θ-max samples)
+   (map polar->cartesian θs (map* f1 θs))
+   (map polar->cartesian θs (map* f2 θs))
    #:x-min x-min #:x-max x-max #:y-min y-min #:y-max y-max
    #:color color #:style style
    #:line1-color line1-color #:line1-width line1-width #:line1-style line1-style
diff --git a/collects/plot/plot2d/kde.rkt b/collects/plot/plot2d/kde.rkt
index 26dac605e6..3495221d38 100644
--- a/collects/plot/plot2d/kde.rkt
+++ b/collects/plot/plot2d/kde.rkt
@@ -1,12 +1,12 @@
 #lang racket/base
 
 (require racket/flonum racket/list racket/promise racket/math racket/contract
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt"
          "../common/utils.rkt"
          "line.rkt")
 
-(provide kde density)
+(provide (all-defined-out))
 
 (define (factorial n)
   (if (zero? n) 1 (* n (factorial (sub1 n)))))
diff --git a/collects/plot/plot2d/line.rkt b/collects/plot/plot2d/line.rkt
index 2d042a11a4..f034d3e3ce 100644
--- a/collects/plot/plot2d/line.rkt
+++ b/collects/plot/plot2d/line.rkt
@@ -3,10 +3,10 @@
 ;; Line renderers.
 
 (require racket/contract racket/class racket/match racket/math racket/list
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide lines parametric polar function inverse)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Lines, parametric, polar
@@ -50,7 +50,7 @@
                      [#:alpha alpha (real-in 0 1) (line-alpha)]
                      [#:label label (or/c string? #f) #f]
                      ) renderer2d?
-  (lines (sample-parametric f t-min t-max samples)
+  (lines (map f (linear-seq t-min t-max samples))
          #:x-min x-min #:x-max x-max #:y-min y-min #:y-max y-max
          #:color color #:width width #:style style #:alpha alpha
          #:label label))
@@ -66,7 +66,8 @@
                 [#:alpha alpha (real-in 0 1) (line-alpha)]
                 [#:label label (or/c string? #f) #f]
                 ) renderer2d?
-  (lines (sample-polar f θ-min θ-max samples)
+  (lines (let ([θs  (linear-seq θ-min θ-max samples)])
+           (map polar->cartesian θs (map* f θs)))
          #:x-min x-min #:x-max x-max #:y-min y-min #:y-max y-max
          #:color color #:width width #:style style #:alpha alpha
          #:label label))
diff --git a/collects/plot/plot2d/plot.rkt b/collects/plot/plot2d/plot.rkt
index 697a100759..99ec9cecb6 100644
--- a/collects/plot/plot2d/plot.rkt
+++ b/collects/plot/plot2d/plot.rkt
@@ -6,21 +6,20 @@
          slideshow/pict
          unstable/parameter-group
          unstable/lazy-require
-         (for-syntax racket/base
-                     syntax/strip-context
-                     racket/syntax)
-         plot/custom plot/utils
-         "../common/contract-doc.rkt"
+         "../common/contract.rkt"
+         "../common/math.rkt"
+         "../common/parameters.rkt"
+         "../common/plot-element.rkt"
          "../common/file-type.rkt"
          "../common/deprecation-warning.rkt"
-         "../common/utils.rkt"
+         "../common/contract-doc.rkt"
          "area.rkt")
 
 ;; Require lazily: without this, Racket complains while generating documentation:
 ;;   cannot instantiate `racket/gui/base' a second time in the same process
 (lazy-require ["../common/gui.rkt" (make-snip-frame)])
 
-(provide plot/dc plot plot-bitmap plot-pict plot-snip plot-frame plot-file)
+(provide (except-out (all-defined-out) make-snip-frame))
 
 ;; ===================================================================================================
 ;; Plot to a given device context
diff --git a/collects/plot/plot2d/point.rkt b/collects/plot/plot2d/point.rkt
index 8af2b2907c..46c28dfac9 100644
--- a/collects/plot/plot2d/point.rkt
+++ b/collects/plot/plot2d/point.rkt
@@ -3,11 +3,11 @@
 ;; Renderers for points and other point-like things.
 
 (require racket/contract racket/class racket/match racket/math racket/list
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt"
          "clip.rkt")
 
-(provide points vector-field error-bars)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Points (scatter plots)
diff --git a/collects/plot/plot2d/rectangle.rkt b/collects/plot/plot2d/rectangle.rkt
index ce969bab98..2b0da7fbc7 100644
--- a/collects/plot/plot2d/rectangle.rkt
+++ b/collects/plot/plot2d/rectangle.rkt
@@ -3,11 +3,11 @@
 ;; The histogram renderer.
 
 (require racket/match racket/contract racket/class racket/list
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt"
          "../common/utils.rkt")
 
-(provide rectangles area-histogram discrete-histogram)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Rectangles
diff --git a/collects/plot/plot3d/contour.rkt b/collects/plot/plot3d/contour.rkt
index d7ce7bc45b..98bfd72ba8 100644
--- a/collects/plot/plot3d/contour.rkt
+++ b/collects/plot/plot3d/contour.rkt
@@ -1,10 +1,10 @@
 #lang racket/base
 
 (require racket/class racket/match racket/list racket/flonum racket/contract
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide contours3d contour-intervals3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Contour lines in 3D (using marching squares)
diff --git a/collects/plot/plot3d/isosurface.rkt b/collects/plot/plot3d/isosurface.rkt
index cb5554a33f..21126326f8 100644
--- a/collects/plot/plot3d/isosurface.rkt
+++ b/collects/plot/plot3d/isosurface.rkt
@@ -1,11 +1,11 @@
 #lang racket/base
 
 (require racket/class racket/match racket/list racket/flonum racket/contract racket/math
-         plot/custom plot/utils
+         plot/utils
          "../common/marching-cubes.rkt"
          "../common/contract-doc.rkt")
 
-(provide isosurface3d isosurfaces3d polar3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Surfaces of constant value (isosurfaces)
@@ -235,6 +235,18 @@
                  label color 'solid line-color line-width line-style)]
         [else  empty]))
 
+(define 2pi (* 2 pi))
+
+(define ((2d-polar->3d-function f) x y z)
+  (let ([x  (exact->inexact x)]
+        [y  (exact->inexact y)]
+        [z  (exact->inexact z)])
+    (define-values (θ ρ)
+      (cond [(and (fl= x 0.0) (fl= y 0.0))  (values 0.0 0.0)]
+            [else  (values (flmodulo (flatan2 y x) 2pi)
+                           (flatan (fl/ z (distance x y))))]))
+    (fl- (exact->inexact (f θ ρ)) (distance x y z))))
+
 (defproc (polar3d [f (real? real? . -> . real?)]
                   [#:x-min x-min (or/c real? #f) #f] [#:x-max x-max (or/c real? #f) #f]
                   [#:y-min y-min (or/c real? #f) #f] [#:y-max y-max (or/c real? #f) #f]
@@ -247,8 +259,10 @@
                   [#:alpha alpha (real-in 0 1) (surface-alpha)]
                   [#:label label (or/c string? #f) #f]
                   ) renderer3d?
-  (define rvs (filter vregular? (sample-2d-polar f 0 2pi (* 2 samples)
-                                                 (* -1/2 pi) (* 1/2 pi) samples)))
+  (define vs (for*/list ([θ  (in-list (linear-seq 0 2pi (* 4 samples)))]
+                         [ρ  (in-list (linear-seq (* -1/2 pi) (* 1/2 pi) (* 2 samples)))])
+               (3d-polar->3d-cartesian θ ρ (f θ ρ))))
+  (define rvs (filter vregular? vs))
   (cond [(empty? rvs)  (renderer3d #f #f #f #f)]
         [else
          (match-define (list (vector rxs rys rzs) ...) rvs)
diff --git a/collects/plot/plot3d/line.rkt b/collects/plot/plot3d/line.rkt
index 411ad537a7..2df546d1fa 100644
--- a/collects/plot/plot3d/line.rkt
+++ b/collects/plot/plot3d/line.rkt
@@ -1,10 +1,10 @@
 #lang racket/base
 
 (require racket/class racket/match racket/list racket/contract
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide lines3d parametric3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 
@@ -58,5 +58,5 @@
           [#:alpha alpha (real-in 0 1) (line-alpha)]
           [#:label label (or/c string? #f) #f]
           ) renderer3d?
-  (lines3d-renderer (λ () (sample-parametric f t-min t-max (animated-samples samples)))
+  (lines3d-renderer (λ () (map f (linear-seq t-min t-max (animated-samples samples))))
                     x-min x-max y-min y-max z-min z-max color width style alpha label))
diff --git a/collects/plot/plot3d/plot.rkt b/collects/plot/plot3d/plot.rkt
index 74a09f137e..ad0a341843 100644
--- a/collects/plot/plot3d/plot.rkt
+++ b/collects/plot/plot3d/plot.rkt
@@ -1,20 +1,18 @@
 #lang racket/base
 
+;; Procedures that plot 3D renderers.
+
 (require racket/draw racket/snip racket/match racket/list racket/class racket/contract
          slideshow/pict
          unstable/parameter-group
          unstable/lazy-require
-         (for-syntax racket/base)
-         "../common/math.rkt"
-         "../common/file-type.rkt"
-         "../common/area.rkt"
          "../common/contract.rkt"
-         "../common/contract-doc.rkt"
+         "../common/math.rkt"
          "../common/parameters.rkt"
-         "../common/deprecation-warning.rkt"
          "../common/plot-element.rkt"
-         "../common/non-renderer.rkt"
-         "../common/utils.rkt"
+         "../common/file-type.rkt"
+         "../common/deprecation-warning.rkt"
+         "../common/contract-doc.rkt"
          "area.rkt")
 
 ;; Require lazily: without this, Racket complains while generating documentation:
@@ -22,7 +20,7 @@
 (lazy-require ["snip.rkt" (make-3d-plot-snip)]
               ["../common/gui.rkt" (make-snip-frame)])
 
-(provide plot3d/dc plot3d plot3d-bitmap plot3d-pict plot3d-snip plot3d-frame plot3d-file)
+(provide (except-out (all-defined-out) make-3d-plot-snip make-snip-frame))
 
 ;; ===================================================================================================
 ;; Plot to a given device context
diff --git a/collects/plot/plot3d/point.rkt b/collects/plot/plot3d/point.rkt
index 21f6aa6e18..a2c9912872 100644
--- a/collects/plot/plot3d/point.rkt
+++ b/collects/plot/plot3d/point.rkt
@@ -1,10 +1,10 @@
 #lang racket/base
 
 (require racket/class racket/list racket/match racket/contract
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide points3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 
diff --git a/collects/plot/plot3d/rectangle.rkt b/collects/plot/plot3d/rectangle.rkt
index 1baeac6e18..6e312a0277 100644
--- a/collects/plot/plot3d/rectangle.rkt
+++ b/collects/plot/plot3d/rectangle.rkt
@@ -3,10 +3,10 @@
 ;; Functions to create renderers for 3D histograms
 
 (require racket/match racket/list racket/contract racket/class
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide rectangles3d discrete-histogram3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Rectangles
diff --git a/collects/plot/plot3d/surface.rkt b/collects/plot/plot3d/surface.rkt
index 484b8da369..555f69a3e2 100644
--- a/collects/plot/plot3d/surface.rkt
+++ b/collects/plot/plot3d/surface.rkt
@@ -1,10 +1,10 @@
 #lang racket/base
 
 (require racket/class racket/match racket/list racket/flonum racket/contract
-         plot/custom plot/utils
+         plot/utils
          "../common/contract-doc.rkt")
 
-(provide surface3d)
+(provide (all-defined-out))
 
 ;; ===================================================================================================
 ;; Surface plots of R R -> R functions
diff --git a/collects/plot/scribblings/common.rkt b/collects/plot/scribblings/common.rkt
index f1e02a6725..fabe9b1b6d 100644
--- a/collects/plot/scribblings/common.rkt
+++ b/collects/plot/scribblings/common.rkt
@@ -8,6 +8,7 @@
                     plot/utils)
          plot
          plot/utils
+         plot/doc
          plot/common/contract-doc)
 
 (provide (all-defined-out)
@@ -18,6 +19,7 @@
                                   plot
                                   plot/utils))
          (all-from-out plot)
+         (all-from-out plot/doc)
          (all-from-out plot/utils)
          doc-apply)
 
diff --git a/collects/plot/scribblings/contracts.scrbl b/collects/plot/scribblings/contracts.scrbl
index 5f4c713366..e2b50f16f7 100644
--- a/collects/plot/scribblings/contracts.scrbl
+++ b/collects/plot/scribblings/contracts.scrbl
@@ -2,7 +2,7 @@
 
 @(require "common.rkt")
 
-@declare-exporting[plot]
+@declare-exporting[plot/utils]
 
 @title[#:tag "contracts"]{Plot Contracts}
 
@@ -43,7 +43,7 @@ Identifies legal font family values. See @(racket plot-font-family).
 The contract for the @(racket #:sym) arguments in @(racket points) and @(racket points3d), and the parameter @(racket point-sym).
 }
 
-@defthing[known-point-symbols (listof symbol?)]{
+@doc-apply[known-point-symbols]{
 A list containing the symbols that are valid @(racket points) symbols.
 
 @interaction[#:eval plot-eval
diff --git a/collects/plot/scribblings/plot2d.scrbl b/collects/plot/scribblings/plot2d.scrbl
index 9893030dc2..d67f0a7220 100644
--- a/collects/plot/scribblings/plot2d.scrbl
+++ b/collects/plot/scribblings/plot2d.scrbl
@@ -7,7 +7,7 @@
 
 @title[#:tag "plot2d"]{2D Plot Procedures}
 
-@defproc[(plot [renderer-tree (treeof renderer2d?)]
+@defproc[(plot [renderer-tree (treeof (or/c renderer2d? non-renderer?))]
                [#:x-min x-min (or/c real? #f) #f] [#:x-max x-max (or/c real? #f) #f]
                [#:y-min y-min (or/c real? #f) #f] [#:y-max y-max (or/c real? #f) #f]
                [#:width width exact-positive-integer? (plot-width)]
@@ -50,14 +50,14 @@ The @(racket #:lncolor) keyword argument is also accepted for backward compatibi
 }
 
 @deftogether[
-(@defproc[(plot-file [renderer-tree (treeof renderer2d?)]
+(@defproc[(plot-file [renderer-tree (treeof (or/c renderer2d? non-renderer?))]
                      [output (or/c path-string? output-port?)]
                      [kind (one-of/c 'auto 'png 'jpeg 'xmb 'xpm 'bmp 'ps 'pdf 'svg) 'auto]
                      [#:<plot-keyword> <plot-keyword> <plot-keyword-contract>] ...) void?]
- @defproc[(plot-pict [renderer-tree (treeof renderer2d?)] ...) pict?]
- @defproc[(plot-bitmap [renderer-tree (treeof renderer2d?)] ...) (is-a?/c bitmap%)]
- @defproc[(plot-snip [renderer-tree (treeof renderer2d?)] ...) (is-a?/c image-snip%)]
- @defproc[(plot-frame [renderer-tree (treeof renderer2d?)] ...) (is-a?/c frame%)])]{
+ @defproc[(plot-pict [renderer-tree (treeof (or/c renderer2d? non-renderer?))] ...) pict?]
+ @defproc[(plot-bitmap [renderer-tree (treeof (or/c renderer2d? non-renderer?))] ...) (is-a?/c bitmap%)]
+ @defproc[(plot-snip [renderer-tree (treeof (or/c renderer2d? non-renderer?))] ...) (is-a?/c image-snip%)]
+ @defproc[(plot-frame [renderer-tree (treeof (or/c renderer2d? non-renderer?))] ...) (is-a?/c frame%)])]{
 Plot to different backends. Each of these procedures has the same keyword arguments as @(racket plot), except for deprecated keywords.
 
 Use @(racket plot-file) to save a plot to a file.
diff --git a/collects/plot/scribblings/plot3d.scrbl b/collects/plot/scribblings/plot3d.scrbl
index ef8570e021..5201d541f5 100644
--- a/collects/plot/scribblings/plot3d.scrbl
+++ b/collects/plot/scribblings/plot3d.scrbl
@@ -8,7 +8,7 @@
 
 Each 3D plot procedure corresponds with a @(secref "plot2d") procedure. Each behaves the same way as its corresponding 2D procedure, but takes the additional keyword arguments @(racket #:z-min), @(racket #:z-max), @(racket #:angle), @(racket #:altitude) and @(racket #:z-label).
 
-@defproc[(plot3d [renderer-tree (treeof renderer3d?)]
+@defproc[(plot3d [renderer-tree (treeof (or/c renderer3d? non-renderer?))]
                  [#:x-min x-min (or/c real? #f) #f] [#:x-max x-max (or/c real? #f) #f]
                  [#:y-min y-min (or/c real? #f) #f] [#:y-max y-max (or/c real? #f) #f]
                  [#:z-min z-min (or/c real? #f) #f] [#:z-max z-max (or/c real? #f) #f]
@@ -40,14 +40,14 @@ The @(racket #:az) and @(racket #:alt) keyword arguments are backward-compatible
 }
 
 @deftogether[
-(@defproc[(plot3d-file [renderer-tree (treeof renderer3d?)]
+(@defproc[(plot3d-file [renderer-tree (treeof (or/c renderer3d? non-renderer?))]
                        [output (or/c path-string? output-port?)]
                        [kind (one-of/c 'auto 'png 'jpeg 'xmb 'xpm 'bmp 'ps 'pdf 'svg) 'auto]
                        [#:<plot-keyword> <plot-keyword> <plot-keyword-contract>] ...) void?]
- @defproc[(plot3d-pict [renderer-tree (treeof renderer3d?)] ...) pict?]
- @defproc[(plot3d-bitmap [renderer-tree (treeof renderer3d?)] ...) (is-a?/c bitmap%)]
- @defproc[(plot3d-snip [renderer-tree (treeof renderer3d?)] ...) (is-a?/c image-snip%)]
- @defproc[(plot3d-frame [renderer-tree (treeof renderer3d?)] ...) (is-a?/c frame%)])]{
+ @defproc[(plot3d-pict [renderer-tree (treeof (or/c renderer3d? non-renderer?))] ...) pict?]
+ @defproc[(plot3d-bitmap [renderer-tree (treeof (or/c renderer3d? non-renderer?))] ...) (is-a?/c bitmap%)]
+ @defproc[(plot3d-snip [renderer-tree (treeof (or/c renderer3d? non-renderer?))] ...) (is-a?/c image-snip%)]
+ @defproc[(plot3d-frame [renderer-tree (treeof (or/c renderer3d? non-renderer?))] ...) (is-a?/c frame%)])]{
 Plot to different backends. Each of these procedures has the same keyword arguments as @(racket plot3d), except for deprecated keywords.
 
 These procedures correspond with  @(racket plot-file), @(racket plot-pict), @(racket plot-bitmap), @(racket plot-snip) and @(racket plot-frame).
diff --git a/collects/plot/tests/axis-transform-tests.rkt b/collects/plot/tests/axis-transform-tests.rkt
index 2185acfa0a..dc366b7544 100644
--- a/collects/plot/tests/axis-transform-tests.rkt
+++ b/collects/plot/tests/axis-transform-tests.rkt
@@ -5,7 +5,6 @@
          plot/utils
          plot/common/contract
          plot/common/contract-doc
-         ;plot/common/axis-transform
          )
 
 (x-axis-ticks? #f)
diff --git a/collects/plot/tests/low-level-tests.rkt b/collects/plot/tests/low-level-tests.rkt
index 727e7bd5b1..2638120492 100755
--- a/collects/plot/tests/low-level-tests.rkt
+++ b/collects/plot/tests/low-level-tests.rkt
@@ -2,9 +2,19 @@
 
 (require rackunit racket/date
          plot plot/utils
-         plot/common/date-time
-         plot/common/vector
-         plot/common/utils)
+         plot/common/utils
+         (only-in plot/common/math
+                  vector-andmap
+                  vector-ormap)
+         (only-in plot/common/date-time
+                  utc-seconds-round-year
+                  utc-seconds-round-month
+                  seconds-per-minute
+                  seconds-per-hour
+                  seconds-per-day
+                  seconds-per-week)
+         (only-in plot/common/format
+                  int-str->e-str frac-str->e-str))
 
 (check-equal? (linear-seq 0 1 2 #:start? #t #:end? #t) '(0 1))
 (check-equal? (linear-seq 0 1 2 #:start? #t #:end? #f) '(0 2/3))
@@ -15,6 +25,19 @@
            (λ () (vector-field (λ (v [z 0]) v) -4 4 -4 4))
            "Exception should be 'two of the clauses in the or/c might both match' or similar")
 
+;; ===================================================================================================
+;; Formatting
+
+(check-equal? (int-str->e-str "") "0")
+(check-equal? (int-str->e-str "0") "0")
+(check-equal? (int-str->e-str "10") "1×10\u00b9")
+
+(check-equal? (frac-str->e-str "") "0")
+(check-equal? (frac-str->e-str "0") "0")
+(check-equal? (frac-str->e-str "00") "0")
+(check-equal? (frac-str->e-str "1") "1×10\u207b\u00b9")
+(check-equal? (frac-str->e-str "01") "1×10\u207b\u00b2")
+
 ;; ===================================================================================================
 ;; Date rounding
 
diff --git a/collects/plot/tests/pen-brush-hsv.rkt b/collects/plot/tests/pen-brush-hsv.rkt
index cbc3656050..e72df799d8 100644
--- a/collects/plot/tests/pen-brush-hsv.rkt
+++ b/collects/plot/tests/pen-brush-hsv.rkt
@@ -2,8 +2,6 @@
 
 (require plot plot/utils)
 
-(define (real-modulo x y) (- x (* y (floor (/ x y)))))
-
 (define (rgb->hsv rgb)
   (match-define (list r g b) (map (λ (x) (/ x 255)) rgb))
   (define mx (max r g b))
diff --git a/collects/plot/tests/tick-tests.rkt b/collects/plot/tests/tick-tests.rkt
index db64200d36..3d9db7a207 100644
--- a/collects/plot/tests/tick-tests.rkt
+++ b/collects/plot/tests/tick-tests.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require plot (only-in plot/common/math floor-log/base real-modulo))
+(require plot plot/utils)
 
 (plot-font-family 'swiss)
 
@@ -99,7 +99,7 @@
             (y-ticks (list (tick 1/4 #t "1/4") (tick -1/4 #f "")))))
 
 (parameterize ([plot-z-max-ticks  5])
-  (plot3d (list (surface3d (λ (x y) (* 2 (+ (sin x) (cos y)))) -4 4 -4 4)
+  (plot3d (list (surface3d (λ (x y) (* 2 (+ (sin x) (cos y)))) -4 4 -4 4 #:alpha 1/2)
                 (x-ticks (list (tick 1.5 #t "3/2") (tick 3 #t "Three")))
                 (y-ticks (list (tick 1/3 #t "1/3") (tick -1/3 #f "1/3")))
                 (z-ticks (list (tick pi #f "π") (tick (- pi) #t "-π"))))))
diff --git a/collects/plot/utils.rkt b/collects/plot/utils.rkt
index f6e4404a15..216fb85269 100644
--- a/collects/plot/utils.rkt
+++ b/collects/plot/utils.rkt
@@ -1,27 +1,29 @@
 #lang racket/base
 
-(require "common/math.rkt")
-(provide (all-from-out "common/math.rkt"))
+(require "common/contract.rkt"
+         "common/marching-squares.rkt"
+         "contracted/parameters.rkt"
+         "contracted/math.rkt"
+         "contracted/axis-transform.rkt"
+         "contracted/ticks.rkt"
+         "contracted/format.rkt"
+         "contracted/draw.rkt"
+         "contracted/sample.rkt"
+         "contracted/samplers.rkt"
+         "contracted/legend.rkt"
+         "contracted/plot-element.rkt"
+         "contracted/date-time.rkt")
 
-(require "common/format.rkt")
-(provide digits-for-range
-         real->plot-label
-         ->plot-label
-         real->string/trunc)
-
-(require "common/draw.rkt")
-(provide color-seq color-seq*
-         ->color
-         ->pen-color ->brush-color
-         ->pen-style ->brush-style
-         alpha-expt)
-
-(require "common/axis-transform.rkt")
-(provide (struct-out invertible-function))
-
-(require "common/sample.rkt")
-(provide linear-seq linear-seq* nonlinear-seq
-         (struct-out mapped-function))
-
-(require "common/contract.rkt")
-(provide (all-from-out "common/contract.rkt"))
+(provide (all-from-out "common/contract.rkt")
+         (all-from-out "common/marching-squares.rkt")
+         (all-from-out "contracted/parameters.rkt")
+         (all-from-out "contracted/math.rkt")
+         (all-from-out "contracted/axis-transform.rkt")
+         (all-from-out "contracted/ticks.rkt")
+         (all-from-out "contracted/format.rkt")
+         (all-from-out "contracted/draw.rkt")
+         (all-from-out "contracted/sample.rkt")
+         (all-from-out "contracted/samplers.rkt")
+         (all-from-out "contracted/legend.rkt")
+         (all-from-out "contracted/plot-element.rkt")
+         (all-from-out "contracted/date-time.rkt"))
diff --git a/collects/tests/unstable/latent-contract.rkt b/collects/tests/unstable/latent-contract.rkt
new file mode 100644
index 0000000000..689f077691
--- /dev/null
+++ b/collects/tests/unstable/latent-contract.rkt
@@ -0,0 +1,33 @@
+#lang racket/load
+
+(require rackunit)
+
+(module module0 racket/base
+  (require racket/contract unstable/latent-contract)
+  
+  (provide identity listify)
+  
+  (define/latent-contract (identity x) (real? . -> . real?)
+    x)
+  (define/latent-contract (listify x) (parametric->/c [a] (a . -> . (listof a)))
+    (list x)))
+
+(module module1 racket/base
+  (require 'module0 unstable/latent-contract)
+  (provide (activate-contract-out identity listify)))
+
+(require 'module0)
+
+(check-true (procedure? identity))
+(check-true (procedure? listify))
+(check-equal? (identity 1) 1)
+(check-equal? (identity 'x) 'x)
+(check-equal? (listify 1) (list 1))
+
+(require 'module1)
+
+(check-true (procedure? identity))
+(check-true (procedure? listify))
+(check-equal? (identity 1) 1)
+(check-exn exn:fail:contract? (λ () (identity 'x)))
+(check-equal? (listify 1) (list 1))
diff --git a/collects/unstable/latent-contract.rkt b/collects/unstable/latent-contract.rkt
new file mode 100644
index 0000000000..11e2697d70
--- /dev/null
+++ b/collects/unstable/latent-contract.rkt
@@ -0,0 +1,74 @@
+#lang racket/base
+
+(require (for-syntax racket/base
+                     racket/syntax
+                     syntax/parse
+                     racket/provide-transform
+                     syntax/define)
+         racket/contract)
+
+(provide define/latent-contract activate-contract-out)
+
+(begin-for-syntax
+  (struct value/latent-contract (value contract)
+    #:property prop:procedure
+    (λ (v/lc stx)
+      (define value (value/latent-contract-value v/lc))
+      (syntax-case stx ()
+        [(_ . args)  (quasisyntax/loc stx (#,value . args))]
+        [_           (quasisyntax/loc stx #,value)]))))
+
+(define-syntax (define/latent-contract stx)
+  (syntax-parse stx
+    [(_ (head . args) contract:expr body:expr ...+)
+     (define-values (name value)
+       (normalize-definition (syntax/loc stx (define (head . args) body ...)) #'lambda #t #t))
+     (syntax-protect
+      (quasisyntax/loc stx
+        (define/latent-contract #,name contract #,value)))]
+    [(_ name:id contract:expr value:expr)
+     (with-syntax ([value-name     (format-id #f "~a" #'name)]
+                   [contract-name  (format-id #f "~a-contract" #'name)])
+       (syntax-protect
+        (syntax/loc stx
+          (begin (define value-name value)
+                 (define contract-name contract)
+                 (define-syntax name
+                   (value/latent-contract #'value-name #'contract-name))))))]))
+
+(define-for-syntax (activate->contract-out stx id)
+  (let* ([err  (λ () (raise-syntax-error 'activate-contract-out "no latent contract" id))]
+         [v/lc  (syntax-local-value id err)])
+    (when (not (value/latent-contract? v/lc)) (err))
+    (with-syntax ([contract  (value/latent-contract-contract v/lc)])
+      (quasisyntax/loc stx [#,id contract]))))
+
+(define-syntax activate-contract-out/end
+  (make-provide-pre-transformer
+   (λ (stx modes)
+     (syntax-case stx ()
+       [(_ id ...)  (with-syntax ([(item ...)  (for/list ([id  (in-list (syntax->list #'(id ...)))])
+                                                 (activate->contract-out stx id))])
+                      (pre-expand-export
+                       (syntax-protect
+                        (syntax/loc stx (contract-out item ...)))
+                       modes))]))))
+
+(define-for-syntax (modes->abs-modes modes)
+  (map (λ (mode) (and mode (+ mode (syntax-local-phase-level))))
+       (if (null? modes) '(0) modes)))
+
+(define-for-syntax (make-lifting-provide-pre-transformer target-id)
+  (make-provide-pre-transformer
+   (λ (stx modes)
+     (syntax-case stx ()
+       [(_ args ...)  (let ()
+                        (for ([mode  (in-list (modes->abs-modes modes))])
+                          (syntax-local-lift-module-end-declaration
+                           (syntax-protect
+                            (quasisyntax/loc stx
+                              (provide (for-meta #,mode (#,target-id args ...)))))))
+                        (syntax/loc stx (combine-out)))]))))
+
+(define-syntax activate-contract-out
+  (make-lifting-provide-pre-transformer #'activate-contract-out/end))