diff --git a/collects/web-server/bindings.ss b/collects/web-server/bindings.ss
index 1d8b699be0..d4846adf83 100644
--- a/collects/web-server/bindings.ss
+++ b/collects/web-server/bindings.ss
@@ -1,9 +1,7 @@
 (module bindings mzscheme
-  (require (lib "list.ss"))
-  (provide extract-binding/single
-           extract-bindings
-           exists-binding?)
-                
+  (require (lib "list.ss")
+           (lib "contract.ss"))
+  
   ; extract-binding/single : sym (listof (cons str str)) -> str
   (define (extract-binding/single name bindings)
     (define lst (extract-bindings name bindings))
@@ -24,4 +22,9 @@
   (define (exists-binding? name bindings)
     (if (assq name bindings)
         #t
-        #f)))
\ No newline at end of file
+        #f))
+  
+  (provide/contract
+   [extract-binding/single (symbol? (listof (cons/c symbol? any/c)) . -> . any/c)]
+   [extract-bindings (symbol? (listof (cons/c symbol? any/c)) . -> . (listof any/c))]
+   [exists-binding? (symbol? (listof (cons/c symbol? any/c)) . -> . boolean?)]))
\ No newline at end of file
diff --git a/collects/web-server/configuration-structures.ss b/collects/web-server/configuration-structures.ss
index 3768301d93..12582865ed 100644
--- a/collects/web-server/configuration-structures.ss
+++ b/collects/web-server/configuration-structures.ss
@@ -1,19 +1,22 @@
 (module configuration-structures mzscheme
-  (require "util.ss"
+  (require (lib "unitsig.ss")
+           (lib "contract.ss")
+           (lib "url.ss" "net"))
+  (require "response-structs.ss"
            "configuration-table-structs.ss")
-  (provide (struct timeouts (default-servlet password servlet-connection file-per-byte file-base))
-           (struct paths (host-base log htdocs mime-types servlet)))
-
+  
   ; configuration is now a unit.  See sig.ss
-
+  ; XXX contract
+  (define configuration?
+    unit/sig?)
+  
   ; host = (make-host (listof str) sym string
-  ;                   passwords resopnders timeouts paths)
-  (provide-define-struct
-   host (indices log-format log-path passwords responders timeouts paths))
-
+  ;                   passwords responders timeouts paths)
+  (define-struct host (indices log-format log-path passwords responders timeouts paths))  
+  
   ; passwords = (listof (list* relm:str protected-dir-regexp:str
   ;                            (listof (list user:sym password:str))))
-
+  
   ; responders = (make-responders (url tst -> response)
   ;                               (url tst -> response)
   ;                               (url (cons sym str) -> response)
@@ -22,6 +25,31 @@
   ;                               (url -> response)
   ;                               response
   ;                               response)
-  (provide-define-struct
-   responders
-   (servlet servlet-loading authentication servlets-refreshed passwords-refreshed file-not-found protocol collect-garbage)))
+  (define-struct responders
+    (servlet servlet-loading authentication servlets-refreshed passwords-refreshed file-not-found protocol collect-garbage))
+
+  (provide ; all-from
+   (struct timeouts (default-servlet password servlet-connection file-per-byte file-base))
+   (struct paths (host-base log htdocs mime-types servlet)))
+  (provide/contract
+   [configuration? (any/c . -> . boolean?)]
+   [struct host 
+           ([indices (listof string?)]
+            [log-format symbol?]
+            [log-path (or/c false/c path? string?)]
+            [passwords (or/c false/c path? string?)]
+            #;[passwords (listof (cons/c string?
+                                       (cons/c string?
+                                               (listof (list/c symbol? string?)))))]
+            [responders responders?]
+            [timeouts timeouts?]
+            [paths paths?])]
+   [struct responders
+           ([servlet (url? any/c . -> . response?)]
+            [servlet-loading (url? any/c . -> . response?)]
+            [authentication (url? (cons/c symbol? string?) . -> . response?)]
+            [servlets-refreshed (-> response?)]
+            [passwords-refreshed (-> response?)]
+            [file-not-found (url? . -> . response?)]
+            [protocol (url? . -> . response?)]
+            [collect-garbage (-> response?)])]))
diff --git a/collects/web-server/configuration-table-structs.ss b/collects/web-server/configuration-table-structs.ss
index 3b8ec6f1c4..5777164855 100644
--- a/collects/web-server/configuration-table-structs.ss
+++ b/collects/web-server/configuration-table-structs.ss
@@ -1,24 +1,55 @@
 (module configuration-table-structs mzscheme
-  (require "util.ss")
+  (require (lib "contract.ss"))
   
   ; configuration-table = (make-configuration-table nat nat num host-table (listof (cons str host-table)))
-  (provide-define-struct
-   configuration-table
-   (port max-waiting initial-connection-timeout default-host virtual-hosts))
+  (define-struct configuration-table
+    (port max-waiting initial-connection-timeout default-host virtual-hosts))
   
   ; host-table = (make-host-table (listof str) sym messages timeouts paths)
-  (provide-define-struct host-table (indices log-format messages timeouts paths))
-  
-  ; passwords = (listof (list* relm:str protected-dir-regexp:str (listof (list user:sym password:str))))
-  ; passwords moved back to a separate file
+  (define-struct host-table (indices log-format messages timeouts paths))
   
   ; messages = (make-messages str^6)
-  (provide-define-struct messages
-    (servlet ;servlet-loading
-     authentication servlets-refreshed passwords-refreshed file-not-found protocol collect-garbage))
-  
+  (define-struct messages
+    (servlet authentication servlets-refreshed passwords-refreshed file-not-found protocol collect-garbage))
+
   ; timeouts = (make-timeouts nat^5)
-  (provide-define-struct timeouts (default-servlet password servlet-connection file-per-byte file-base))
+  (define-struct timeouts (default-servlet password servlet-connection file-per-byte file-base))
   
   ; paths = (make-paths str^6)
-  (provide-define-struct paths (conf host-base log htdocs servlet mime-types passwords)))
+  (define-struct paths (conf host-base log htdocs servlet mime-types passwords))
+  
+  (provide/contract
+   [struct configuration-table
+           ([port natural-number/c]
+            [max-waiting natural-number/c]
+            [initial-connection-timeout natural-number/c]
+            [default-host host-table?]
+            [virtual-hosts (listof (cons/c string? host-table?))])]
+   [struct host-table 
+           ([indices (listof string?)]
+            [log-format symbol?]
+            [messages messages?]
+            [timeouts timeouts?]
+            [paths paths?])]
+   [struct messages
+           ([servlet string?]
+            [authentication string?]
+            [servlets-refreshed string?]
+            [passwords-refreshed string?]
+            [file-not-found string?]
+            [protocol string?]
+            [collect-garbage string?])]
+   [struct timeouts 
+           ([default-servlet number?]
+            [password number?]
+            [servlet-connection number?]
+            [file-per-byte number?]
+            [file-base number?])]
+   [struct paths 
+           ([conf (or/c false/c path? string?)]
+            [host-base (or/c false/c path? string?)]
+            [log (or/c false/c path? string?)]
+            [htdocs (or/c false/c path? string?)]
+            [servlet (or/c false/c path? string?)]
+            [mime-types (or/c false/c path? string?)]
+            [passwords (or/c false/c path? string?)])]))
diff --git a/collects/web-server/configuration-util.ss b/collects/web-server/configuration-util.ss
index f1cbb82df3..4496735166 100644
--- a/collects/web-server/configuration-util.ss
+++ b/collects/web-server/configuration-util.ss
@@ -1,8 +1,8 @@
 (module configuration-util mzscheme
-  (require (lib "file.ss")           
+  (require (lib "contract.ss")
+           (lib "file.ss")           
            (lib "pretty.ss"))
-  (require "configuration-table-structs.ss")
-  (provide (all-defined))
+  (require "configuration-table-structs.ss")   
   
   ; write-configuration-table : configuration-table path -> void
   ; writes out the new configuration file
@@ -55,4 +55,9 @@
   (define (write-to-file file-name x)
     (call-with-output-file file-name
       (lambda (out) (pretty-print x out))
-      'truncate)))
\ No newline at end of file
+      'truncate))
+  
+  (provide/contract
+   [write-configuration-table (configuration-table? string? . -> . void)]
+   [format-host (host-table? . -> . list?)]
+   [write-to-file (string? list? . -> . void)]))
\ No newline at end of file
diff --git a/collects/web-server/configuration.ss b/collects/web-server/configuration.ss
index b6f3e3022b..84e549b67e 100644
--- a/collects/web-server/configuration.ss
+++ b/collects/web-server/configuration.ss
@@ -1,5 +1,6 @@
-; configuration language example
 (module configuration mzscheme
+  (require (lib "unitsig.ss")
+           (lib "contract.ss"))
   (require "configuration-structures.ss"
            "configuration-table-structs.ss"
            "sig.ss"
@@ -7,30 +8,6 @@
            "parse-table.ss"
            "private/cache-table.ss"
            "response.ss")
-  (require (lib "unitsig.ss")
-           (lib "contract.ss"))
-  
-  (provide complete-configuration
-           get-configuration
-           build-developer-configuration
-           build-developer-configuration/vhosts ;; added 2/3/05 by Jacob
-           default-configuration-table-path
-           update-configuration)
-  
-  (provide/contract
-   [load-configuration (path? . -> . unit/sig?)]
-   [load-developer-configuration (path? . -> . unit/sig?)])
-  
-  (provide error-response
-           servlet-loading-responder
-           gen-servlet-not-found
-           gen-servlet-responder
-           gen-servlets-refreshed
-           gen-passwords-refreshed
-           gen-authentication-responder
-           gen-protocol-responder
-           gen-file-not-found-responder
-           gen-collect-garbage-responder)
   
   (define default-configuration-table-path
     (build-path (collection-path "web-server") "configuration-table"))
@@ -111,8 +88,6 @@
   
   ; begin stolen from commander.ss, which was stolen from private/drscheme/eval.ss
   ; FIX - abstract this out to a namespace library somewhere (ask Robby and Matthew)
-  
-  
   (define to-be-copied-module-specs
     '(mzscheme
       ;; allow people (SamTH) to use MrEd primitives from servlets.
@@ -122,7 +97,6 @@
       (lib "mred.ss" "mred")
       (lib "servlet.ss" "web-server")))
   
-  
   ; JBC : added error-handler hack; the right answer is only to transfer the 'mred'
   ; module binding when asked to, e.g. by a field in the configuration file.
   ; GregP: put this back in if Sam's code breaks
@@ -203,7 +177,7 @@
   ; gen-servlet-responder : str -> url tst -> response
   (define (gen-servlet-responder servlet-error-file)
     (lambda (url exn)
-      ; more here - use separate log file
+      ; XXX use separate log file
       ((error-display-handler)
        (format "Servlet exception:\n~a\n" (exn-message exn))
        exn)
@@ -296,4 +270,28 @@
                    (and (regexp-match (car x) host-name-possibly-followed-by-a-collon-and-a-port-number)
                         (cadr x)))
                  expanded-virtual-host-table)
-          default-host))))
+          default-host)))
+  
+  (provide/contract
+   [complete-configuration (string? configuration-table? . -> . configuration?)]
+   [get-configuration (string? . -> . configuration-table?)]
+   ; XXX contract
+   [build-developer-configuration (list? . -> . configuration?)]
+   ; XXX contract
+   [build-developer-configuration/vhosts (list? . -> . configuration?)]
+   [default-configuration-table-path path?]
+   [update-configuration (configuration? (listof (cons/c symbol? any/c)) . -> . configuration?)]
+   [load-configuration (path? . -> . configuration?)]
+   [load-developer-configuration (path? . -> . configuration?)])  
+  (provide/contract
+   [error-response ((natural-number/c string? string?) (listof (cons/c symbol? string?)) . ->* . (response?))]
+   ; XXX contract
+   [servlet-loading-responder (string? any/c . -> . response?)]
+   [gen-servlet-not-found (string? . -> . (string? . -> . response?))]
+   [gen-servlet-responder (string? . -> . (string? any/c . -> . response?))]
+   [gen-servlets-refreshed (string? . -> . (-> response?))]
+   [gen-passwords-refreshed (string? . -> . (-> response?))]
+   [gen-authentication-responder (string? . -> . (string? (cons/c symbol? string?) . -> . response?))]
+   [gen-protocol-responder (string? . -> . (string? . -> . response?))]
+   [gen-file-not-found-responder (string? . -> . (string? . -> . response?))]
+   [gen-collect-garbage-responder (string? . -> . (-> response?))]))
\ No newline at end of file
diff --git a/collects/web-server/configure.ss b/collects/web-server/configure.ss
index e3f5fb2cd6..331811673d 100644
--- a/collects/web-server/configure.ss
+++ b/collects/web-server/configure.ss
@@ -1,5 +1,4 @@
 (module configure mzscheme
-  (provide servlet servlet-maker)
   (require (lib "unitsig.ss")
            (lib "servlet-sig.ss" "web-server")
            (lib "url.ss" "net")
@@ -7,12 +6,17 @@
            (lib "list.ss")
            (lib "pretty.ss")
            (lib "file.ss")
+           (lib "contract.ss")
            (only (lib "configuration.ss" "web-server")
                  default-configuration-table-path)
            (lib "configuration-table-structs.ss" "web-server")
            (lib "parse-table.ss" "web-server")
            (lib "configuration-util.ss" "web-server")
            (all-except (lib "util.ss" "web-server") translate-escapes))
+  (provide/contract
+   [servlet unit/sig?]
+   ; XXX contract
+   [servlet-maker (string? . -> . unit/sig?)])
   
   ;; FIX
   ; - fuss with changing absolute paths into relative ones internally
diff --git a/collects/web-server/dispatch-server-sig.ss b/collects/web-server/dispatch-server-sig.ss
new file mode 100644
index 0000000000..083a5220ce
--- /dev/null
+++ b/collects/web-server/dispatch-server-sig.ss
@@ -0,0 +1,13 @@
+(module dispatch-server-sig mzscheme
+  (require (lib "unitsig.ss"))
+
+  (define-signature dispatch-server^
+    (serve
+     serve-ports))
+  
+  (define-signature dispatch-server-config^
+    (port listen-ip max-waiting initial-connection-timeout
+          read-request dispatch))
+  
+  (provide ; XXX contract signature
+   dispatch-server^ dispatch-server-config^))
\ No newline at end of file
diff --git a/collects/web-server/dispatch-server-unit.ss b/collects/web-server/dispatch-server-unit.ss
new file mode 100644
index 0000000000..d182817988
--- /dev/null
+++ b/collects/web-server/dispatch-server-unit.ss
@@ -0,0 +1,81 @@
+(module dispatch-server-unit mzscheme
+  (require (lib "tcp-sig.ss" "net")
+           (lib "unitsig.ss")
+           (lib "thread.ss")
+           (lib "contract.ss")
+           (lib "kw.ss"))
+  (require "web-server-structs.ss"
+           "connection-manager.ss"
+           "dispatch-server-sig.ss")
+  
+  (provide/contract
+   ; XXX contract
+   [dispatch-server@ unit/sig?]) 
+  
+  ;; ****************************************  
+  (define dispatch-server@
+    (unit/sig dispatch-server^
+      (import net:tcp^ (config : dispatch-server-config^))
+      
+      ;; serve: -> -> void
+      ;; start the server and return a thunk to shut it down
+      (define (serve)
+        (define the-server-custodian (make-custodian))
+        (start-connection-manager the-server-custodian)
+        (parameterize ([current-custodian the-server-custodian]
+                       [current-server-custodian the-server-custodian]
+                       [current-thread-initial-stack-size 3])
+          (thread
+           (lambda ()
+             (run-server config:port 
+                         handle-connection
+                         #f
+                         (lambda (exn)
+                           #f)
+                         (lambda (p mw re)
+                           (tcp-listen p config:max-waiting #t config:listen-ip))
+                         tcp-close
+                         tcp-accept
+                         tcp-accept/enable-break))))
+        (lambda ()
+          (custodian-shutdown-all the-server-custodian)))
+      
+      ;; serve-ports : input-port output-port -> void
+      ;; returns immediately, spawning a thread to handle
+      ;; the connection
+      ;; NOTE: (GregP) should allow the user to pass in a connection-custodian
+      (define (serve-ports ip op)
+        (define server-cust (make-custodian))
+        (start-connection-manager server-cust)
+        (parameterize ([current-custodian server-cust]
+                       [current-server-custodian server-cust])
+          (define connection-cust (make-custodian))
+          (parameterize ([current-custodian connection-cust])
+            (thread
+             (lambda ()
+               (handle-connection ip op
+                                  (lambda (ip)
+                                    (values "127.0.0.1"
+                                            "127.0.0.1"))))))))
+      
+      ;; handle-connection : input-port output-port (input-port -> string string) -> void
+      ;; returns immediately, spawning a thread to handle
+      (define/kw (handle-connection ip op
+                                    #:optional
+                                    [port-addresses tcp-addresses])
+        (define conn
+          (new-connection config:initial-connection-timeout
+                          ip op (current-custodian) #f))
+        (with-handlers ([exn:fail:network?
+                         (lambda (e)
+                           (kill-connection! conn)
+                           (raise e))])
+          (let connection-loop ()
+            (define-values (req close?) (config:read-request conn config:port port-addresses))
+            (adjust-connection-timeout! conn config:initial-connection-timeout)
+            (config:dispatch conn req)
+            (unless (connection-close? conn)
+              (set-connection-close?! conn close?))
+            (cond
+              [(connection-close? conn) (kill-connection! conn)]
+              [else (connection-loop)])))))))
\ No newline at end of file
diff --git a/collects/web-server/dispatchers/dispatch-files.ss b/collects/web-server/dispatchers/dispatch-files.ss
index 8fee10ef1f..778f85cbc4 100644
--- a/collects/web-server/dispatchers/dispatch-files.ss
+++ b/collects/web-server/dispatchers/dispatch-files.ss
@@ -2,14 +2,17 @@
   (require (lib "url.ss" "net")
            (lib "xml.ss" "xml")
            (lib "kw.ss")
-           (lib "list.ss"))
+           (lib "list.ss")
+           (lib "contract.ss"))
   (require "dispatch.ss"
            "../configuration.ss"
            "../util.ss"
            "../mime-types.ss"
-           "../response.ss")  
-  (provide interface-version
-           make)
+           "../response.ss")
+  (provide/contract
+   [interface-version dispatcher-interface-version?])
+  (provide ; XXX contract kw
+   make)
   
   (define interface-version 'v1)
   (define/kw (make #:key 
diff --git a/collects/web-server/dispatchers/dispatch-host.ss b/collects/web-server/dispatchers/dispatch-host.ss
index 572d81aa4b..f552ef7434 100644
--- a/collects/web-server/dispatchers/dispatch-host.ss
+++ b/collects/web-server/dispatchers/dispatch-host.ss
@@ -1,11 +1,12 @@
 (module dispatch-host mzscheme
+  (require (lib "contract.ss"))
   (require "dispatch.ss"
            "../servlet-helpers.ss")
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?]
+   [make ((symbol? . -> . dispatcher?) . -> . dispatcher?)])
   
   (define interface-version 'v1)
-  (define (make lookup-dispatcher)
-    (lambda (conn req)
-      (let* ([host (get-host (request-uri req) (request-headers/raw req))])
-        ((lookup-dispatcher host) conn req)))))
\ No newline at end of file
+  (define ((make lookup-dispatcher) conn req)
+    (define host (get-host (request-uri req) (request-headers/raw req)))
+    ((lookup-dispatcher host) conn req)))
\ No newline at end of file
diff --git a/collects/web-server/dispatchers/dispatch-log.ss b/collects/web-server/dispatchers/dispatch-log.ss
index 50b62b6b84..60c0ff3ac7 100644
--- a/collects/web-server/dispatchers/dispatch-log.ss
+++ b/collects/web-server/dispatchers/dispatch-log.ss
@@ -3,11 +3,14 @@
            (lib "date.ss")
            (lib "kw.ss")
            (lib "async-channel.ss")
-           (lib "plt-match.ss"))
+           (lib "plt-match.ss")
+           (lib "contract.ss"))
   (require "dispatch.ss"
            "../servlet-helpers.ss")  
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?])
+  (provide ; XXX contract kw
+   make)  
   
   (define interface-version 'v1)
   (define/kw (make #:key 
diff --git a/collects/web-server/dispatchers/dispatch-passwords.ss b/collects/web-server/dispatchers/dispatch-passwords.ss
index 1efa3dfe0d..70feca3762 100644
--- a/collects/web-server/dispatchers/dispatch-passwords.ss
+++ b/collects/web-server/dispatchers/dispatch-passwords.ss
@@ -1,13 +1,16 @@
 (module dispatch-passwords mzscheme
-  (require (lib "kw.ss"))
+  (require (lib "kw.ss")
+           (lib "contract.ss"))
   (require "dispatch.ss"
            (all-except "../util.ss" translate-escapes)
            "../configuration.ss"
            "../servlet-helpers.ss"
            "../connection-manager.ss"
            "../response.ss")  
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?])
+  (provide ; XXX contract kw
+   make)
   
   (define interface-version 'v1)
   (define/kw (make #:key
diff --git a/collects/web-server/dispatchers/dispatch-pathprocedure.ss b/collects/web-server/dispatchers/dispatch-pathprocedure.ss
index a6710fc05b..c1d052e6b5 100644
--- a/collects/web-server/dispatchers/dispatch-pathprocedure.ss
+++ b/collects/web-server/dispatchers/dispatch-pathprocedure.ss
@@ -1,9 +1,11 @@
 (module dispatch-pathprocedure mzscheme
+  (require (lib "contract.ss"))
   (require "dispatch.ss"
            "../util.ss"
            "../response.ss")
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?]
+   [make (string? (-> response?) . -> . dispatcher?)])
   
   (define interface-version 'v1)
   (define ((make the-path procedure) conn req)
diff --git a/collects/web-server/dispatchers/dispatch-sequencer.ss b/collects/web-server/dispatchers/dispatch-sequencer.ss
index ade520e799..cf7ae402c3 100644
--- a/collects/web-server/dispatchers/dispatch-sequencer.ss
+++ b/collects/web-server/dispatchers/dispatch-sequencer.ss
@@ -1,8 +1,11 @@
 (module dispatch-sequencer mzscheme
-  (require (lib "list.ss"))
+  (require (lib "list.ss")
+           (lib "contract.ss"))
   (require "dispatch.ss")
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?])
+  (provide ; XXX contract kw
+   make)
   
   (define interface-version 'v1)
   (define ((make . dispatchers) conn req)
diff --git a/collects/web-server/dispatchers/dispatch-servlets.ss b/collects/web-server/dispatchers/dispatch-servlets.ss
index e50ec2660c..4a10cc0356 100644
--- a/collects/web-server/dispatchers/dispatch-servlets.ss
+++ b/collects/web-server/dispatchers/dispatch-servlets.ss
@@ -2,7 +2,8 @@
   (require (lib "url.ss" "net")
            (lib "kw.ss")
            (lib "plt-match.ss")
-           (lib "unitsig.ss"))
+           (lib "unitsig.ss")
+           (lib "contract.ss"))
   (require "dispatch.ss"
            "../web-server-structs.ss"
            "../connection-manager.ss"
@@ -13,11 +14,15 @@
            (all-except "../util.ss" translate-escapes)
            "../managers/manager.ss"
            "../managers/timeouts.ss"
+           "../managers/lru.ss"
            "../private/url.ss"
            "../private/servlet.ss"
            "../private/cache-table.ss")  
-  (provide interface-version
-           make)
+  (provide/contract
+   [interface-version dispatcher-interface-version?])
+  (provide ; XXX contract improve
+   ; XXX contract kw
+   make)
   
   (define interface-version 'v1)
   (define/kw (make config:instances config:scripts config:make-servlet-namespace
@@ -362,4 +367,4 @@
              ;; more here - make timeouts proportional to size of bindings
              (servlet-content-producer conn req)]
             [else
-             (next-dispatcher)]))))
\ No newline at end of file
+             (next-dispatcher)]))))
diff --git a/collects/web-server/dispatchers/dispatch.ss b/collects/web-server/dispatchers/dispatch.ss
index 9aa88d8e00..70f3c91dff 100644
--- a/collects/web-server/dispatchers/dispatch.ss
+++ b/collects/web-server/dispatchers/dispatch.ss
@@ -1,14 +1,18 @@
 (module dispatch mzscheme
+  (require (lib "contract.ss"))
   (require "../connection-structs.ss"
            "../request-structs.ss"
            "../response-structs.ss")
-  (require (lib "contract.ss")
-           (lib "list.ss"))
   
-  (provide dispatcher?)
-  (define dispatcher? (connection? request? . -> . response?))
-  
-  (provide next-dispatcher
-           [struct exn:dispatcher ()])
+  (define dispatcher? 
+    (connection? request? . -> . void))
+  (define dispatcher-interface-version?
+    symbol?)
   (define-struct exn:dispatcher ())
-  (define (next-dispatcher) (raise (make-exn:dispatcher))))
\ No newline at end of file
+  (define (next-dispatcher) (raise (make-exn:dispatcher)))
+  
+  (provide/contract
+   [dispatcher? contract?]
+   [dispatcher-interface-version? (any/c . -> . boolean?)]
+   [next-dispatcher (-> void)]
+   [struct exn:dispatcher ()]))
\ No newline at end of file
diff --git a/collects/web-server/launch.ss b/collects/web-server/launch.ss
index bbd0593d43..9161ea9d83 100644
--- a/collects/web-server/launch.ss
+++ b/collects/web-server/launch.ss
@@ -2,12 +2,14 @@
 (module launch mzscheme
   (require (lib "cmdline.ss")
            (lib "pregexp.ss")
-           "util.ss"
+           (lib "contract.ss")
+           (lib "unitsig.ss")
+           (lib "tcp-sig.ss" "net"))
+  (require "util.ss"
            "web-server-unit.ss"
            "sig.ss"
            "configuration.ss"
-           (lib "unitsig.ss")
-           (lib "tcp-sig.ss" "net"))
+           "configuration-structures.ss")
 
   (define configuration@
     (parse-command-line
@@ -58,4 +60,5 @@
      (export (open S)))
     #f net:tcp^)
 
-  (provide serve))
+  (provide ; XXX contract
+   serve))
\ No newline at end of file
diff --git a/collects/web-server/managers/lru.ss b/collects/web-server/managers/lru.ss
index a7a63e214d..1c1873b092 100644
--- a/collects/web-server/managers/lru.ss
+++ b/collects/web-server/managers/lru.ss
@@ -1,8 +1,12 @@
 (module lru mzscheme
   (require (lib "plt-match.ss")
+           (lib "contract.ss")
            (lib "kw.ss"))
-  (require "manager.ss")
-  (provide create-LRU-manager)
+  (require "manager.ss"
+           "../servlet-structs.ss")
+  (provide/contract
+   ; XXX contract kw
+   [create-LRU-manager ((expiration-handler? number? number? (-> boolean?)) any/c . ->* . (manager?))])
   
   ;; Utility
   (define (make-counter)
diff --git a/collects/web-server/managers/manager.ss b/collects/web-server/managers/manager.ss
index f1931a9197..5e0164b0cc 100644
--- a/collects/web-server/managers/manager.ss
+++ b/collects/web-server/managers/manager.ss
@@ -1,5 +1,6 @@
 (module manager mzscheme
-  (provide (all-defined))
+  (require (lib "contract.ss"))
+  (require "../servlet-structs.ss")
   
   (define-struct manager (create-instance 
                           adjust-timeout!
@@ -9,4 +10,20 @@
                           continuation-lookup))
   
   (define-struct (exn:fail:servlet-manager:no-instance exn:fail) (expiration-handler))
-  (define-struct (exn:fail:servlet-manager:no-continuation exn:fail) (expiration-handler)))
+  (define-struct (exn:fail:servlet-manager:no-continuation exn:fail) (expiration-handler))
+  
+  (provide/contract
+   [struct manager ([create-instance (any/c (-> void) . -> . number?)]
+                    [adjust-timeout! (number? number? . -> . void)]
+                    [instance-lookup-data (number? . -> . any/c)]
+                    [clear-continuations! (number? . -> . void)]
+                    [continuation-store! (number? procedure? expiration-handler? . -> . (list/c number? number?))]
+                    [continuation-lookup (number? number? number? . -> . procedure?)])]
+   [struct (exn:fail:servlet-manager:no-instance exn:fail) 
+           ([msg string?]
+            [continuation-marks continuation-mark-set?]
+            [expiration-handler expiration-handler?])]
+   [struct (exn:fail:servlet-manager:no-continuation exn:fail)
+           ([msg string?]
+            [continuation-marks continuation-mark-set?]
+            [expiration-handler expiration-handler?])]))
\ No newline at end of file
diff --git a/collects/web-server/managers/timeouts.ss b/collects/web-server/managers/timeouts.ss
index d446f4448a..5ecfffefb6 100644
--- a/collects/web-server/managers/timeouts.ss
+++ b/collects/web-server/managers/timeouts.ss
@@ -1,8 +1,11 @@
 (module timeouts mzscheme
-  (require (lib "plt-match.ss"))
+  (require (lib "plt-match.ss")
+           (lib "contract.ss"))
   (require "manager.ss")
-  (require "../timer.ss")
-  (provide create-timeout-manager)
+  (require "../timer.ss"
+           "../servlet-structs.ss")
+  (provide/contract
+   [create-timeout-manager (expiration-handler? number? number? . -> . manager?)])
   
   ;; Utility
   (define (make-counter)
diff --git a/collects/web-server/monitor-server.ss b/collects/web-server/monitor-server.ss
index d39a574852..b3b2e6f828 100644
--- a/collects/web-server/monitor-server.ss
+++ b/collects/web-server/monitor-server.ss
@@ -1,13 +1,9 @@
 (module monitor-server mzscheme
   (require (lib "etc.ss")
-           "monitor-poke-web-server.ss"
-           "monitor-emailer.ss"
+           (lib "contract.ss")
            (lib "match.ss"))
-  
-  (provide monitor
-           default-server-port
-           default-poll-frequency-seconds
-           default-server-response-timeout-seconds)
+  (require "monitor-poke-web-server.ss"
+           "monitor-emailer.ss")
   
   (define default-server-port 80)
   (define default-poll-frequency-seconds 3600)
@@ -33,4 +29,10 @@
             [`(ok) (void)]
             [else (send-email (result->message result))])
           (sleep poll-frequency-seconds)
-          (check-server))))))
\ No newline at end of file
+          (check-server)))))
+  
+  (provide/contract 
+   [monitor ((string? string?) (number? number? number?) . -> . void)]
+   [default-server-port number?]
+   [default-poll-frequency-seconds number?]
+   [default-server-response-timeout-seconds number?]))
\ No newline at end of file
diff --git a/collects/web-server/parse-table.ss b/collects/web-server/parse-table.ss
index 5cfc5502ea..560964f1c2 100644
--- a/collects/web-server/parse-table.ss
+++ b/collects/web-server/parse-table.ss
@@ -1,8 +1,8 @@
 (module parse-table mzscheme
-  (require (lib "list.ss"))
+  (require (lib "list.ss")
+           (lib "contract.ss"))
   (require "configuration-table-structs.ss"
            "bindings.ss")
-  (provide parse-configuration-table)
   
   (define (get-binding key bindings default)
     (first (get-binding* key bindings (list default))))
@@ -83,4 +83,8 @@
   
   ; nat? : tst -> bool
   (define (nat? x)
-    (and (number? x) (exact? x) (integer? x) (<= 0 x))))
+    (and (number? x) (exact? x) (integer? x) (<= 0 x)))
+  
+  (provide/contract
+   ; XXX contract
+   [parse-configuration-table (list? . -> . configuration-table?)]))
\ No newline at end of file
diff --git a/collects/web-server/private/cache-table.ss b/collects/web-server/private/cache-table.ss
index da6c2d7087..5ee5743ec6 100644
--- a/collects/web-server/private/cache-table.ss
+++ b/collects/web-server/private/cache-table.ss
@@ -36,5 +36,5 @@
    [rename new-cache-table make-cache-table
            (-> cache-table?)]
    [cache-table-lookup! (cache-table? symbol? (-> any/c) . -> . any/c)]
-   [cache-table-clear! (cache-table? . -> . void?)])
-  (provide cache-table?))
\ No newline at end of file
+   [cache-table-clear! (cache-table? . -> . void?)]
+   [cache-table? (any/c . -> . boolean?)]))
\ No newline at end of file
diff --git a/collects/web-server/private/servlet.ss b/collects/web-server/private/servlet.ss
index 5e2d2ebde6..5fe2842acc 100644
--- a/collects/web-server/private/servlet.ss
+++ b/collects/web-server/private/servlet.ss
@@ -1,10 +1,13 @@
 (module servlet mzscheme
-  (require "../managers/manager.ss")
+  (require (lib "contract.ss"))
+  (require "../managers/manager.ss"
+           "../servlet-structs.ss"
+           "../connection-structs.ss"
+           "../request-structs.ss")
   
   (define-struct (exn:fail:servlet:instance exn:fail) ())
   (define-struct servlet (custodian namespace manager handler))
-  (define-struct servlet-instance-data (mutex context))
-  
+  (define-struct servlet-instance-data (mutex context))  
   (define-struct execution-context (connection request suspend))
   
   (define current-servlet (make-thread-cell #f))
@@ -27,4 +30,26 @@
     (define instance-id (thread-cell-ref current-servlet-instance-id))
     ((manager-instance-lookup-data manager) instance-id))
   
-  (provide (all-defined)))
+  (provide/contract
+   [struct (exn:fail:servlet:instance exn:fail)
+           ([msg string?]
+            [continuation-marks continuation-mark-set?])]
+   [struct servlet 
+           ([custodian custodian?]
+            [namespace namespace?]
+            [manager manager?]
+            [handler (request? . -> . servlet-response?)])]
+   [struct servlet-instance-data
+           ([mutex semaphore?]
+            [context execution-context?])]
+   [struct execution-context 
+           ([connection connection?]
+            [request request?]
+            [suspend procedure?])]
+   ; XXX contract maybe
+   [current-servlet thread-cell?]
+   ; XXX contract maybe
+   [current-servlet-instance-id thread-cell?]
+   [get-current-servlet-instance-id (-> number?)]
+   [current-servlet-manager (-> manager?)]
+   [current-servlet-instance-data (-> servlet-instance-data?)]))
\ No newline at end of file
diff --git a/collects/web-server/private/url.ss b/collects/web-server/private/url.ss
index 6306ddb0a5..0cf0dc3b19 100644
--- a/collects/web-server/private/url.ss
+++ b/collects/web-server/private/url.ss
@@ -4,9 +4,9 @@
            (lib "list.ss")
            (lib "plt-match.ss"))
   
-  (provide
-   match-url-params)
   (provide/contract
+   ; XXX contract maybe
+   [match-url-params (string? . -> . (or/c false/c (list/c string? string? string? string?)))]
    [continuation-url? (url? . -> . (or/c boolean? (list/c number? number? number?)))]
    [embed-ids ((list/c number? number? number?) url? . -> . string?)])
   
diff --git a/collects/web-server/servlet-helpers.ss b/collects/web-server/servlet-helpers.ss
index 2c23bb5936..9db4152830 100644
--- a/collects/web-server/servlet-helpers.ss
+++ b/collects/web-server/servlet-helpers.ss
@@ -1,5 +1,5 @@
 (module servlet-helpers mzscheme
-  (require (lib "list.ss")
+  (require (lib "contract.ss")
            (lib "etc.ss")
            (lib "plt-match.ss")
            (lib "xml.ss" "xml")
@@ -8,21 +8,10 @@
   (require "util.ss"
            "response.ss"
            "request-structs.ss"
-           "bindings.ss")
-  (provide get-host
-           (all-from "bindings.ss")
-           extract-user-pass
-           build-suspender
-           make-html-response/incremental
-           report-errors-to-browser
-           redirect-to
-           permanently
-           temporarily
-           see-other
-           (all-from "request-structs.ss")
-           request-bindings
-           request-headers
-           translate-escapes)
+           "bindings.ss"
+           "servlet-structs.ss")
+  (provide (all-from "bindings.ss")
+           (all-from "request-structs.ss"))  
   
   (define (request-headers request)
     (map (match-lambda
@@ -51,7 +40,7 @@
             [(struct header (_ v))
              (string->symbol (bytes->string/utf-8 v))])]
       [else DEFAULT-HOST-NAME]))
-      
+  
   ; build-suspender : (listof html) (listof html) [(listof (cons sym str))] [(listof (cons sym str))] -> str -> response
   (define build-suspender
     (opt-lambda (title content [body-attributes '([bgcolor "white"])] [head-attributes null])
@@ -134,4 +123,24 @@
   ;; does the second part of the authorization header start with #"Basic "
   (define basic?
     (let ([rx (byte-regexp #"^Basic .*")])
-      (lambda (a) (regexp-match rx a)))))
\ No newline at end of file
+      (lambda (a) (regexp-match rx a))))
+  
+  (provide ; all-from
+   translate-escapes)
+  (provide/contract
+   [get-host (url? (listof header?) . -> . symbol?)]
+   ; XXX contract maybe
+   [extract-user-pass ((listof header?) . -> . (or/c false/c (cons/c string? string?)))]
+   [build-suspender (((listof xexpr?) (listof xexpr?))
+                     ((listof (list/c symbol? string?)) (listof (list/c symbol? string?)))
+                     . opt-> .
+                     (k-url? . -> . xexpr?))]
+   [make-html-response/incremental (((string? . -> . void) . -> . void) . -> . response/incremental?)]
+   [report-errors-to-browser ((servlet-response? . -> . void) . -> . void)]
+   [redirect-to ((string?) (redirection-status?) . opt-> . response/full?)]
+   [permanently redirection-status?]
+   [temporarily redirection-status?]
+   [see-other redirection-status?]
+   [request-bindings (request? . -> . (listof (or/c (cons/c symbol? string?)
+                                                    (cons/c symbol? bytes?))))]
+   [request-headers (request? . -> . (listof (cons/c symbol? string?)))]))
\ No newline at end of file
diff --git a/collects/web-server/servlet-language.ss b/collects/web-server/servlet-language.ss
index 2c64e667af..27caa0bb8b 100644
--- a/collects/web-server/servlet-language.ss
+++ b/collects/web-server/servlet-language.ss
@@ -1,10 +1,11 @@
 (module servlet-language mzscheme
   (require (lib "class.ss")
            (lib "tool.ss" "drscheme")
+           (lib "contract.ss")
            ;(lib "mred.ss" "mred")
            (lib "unitsig.ss"))
-
-  (provide tool@)
+  (provide/contract
+   [tool@ unit/sig?])
 
   (define tool@
     (unit/sig drscheme:tool-exports^
@@ -99,5 +100,4 @@
             ;(language-numbers (list -1000 1000))
             ))
 
-        )))
-  )
+        ))))
\ No newline at end of file
diff --git a/collects/web-server/servlet-structs.ss b/collects/web-server/servlet-structs.ss
new file mode 100644
index 0000000000..622f35c8eb
--- /dev/null
+++ b/collects/web-server/servlet-structs.ss
@@ -0,0 +1,42 @@
+(module servlet-structs mzscheme
+  (require (lib "contract.ss")
+           (lib "xml.ss" "xml"))
+  (require "request-structs.ss"
+           "response-structs.ss")  
+  
+  (define servlet-response?
+    any/c)
+  
+  (define (xexpr/callback? x)
+    (correct-xexpr? x 
+                    (lambda () #t)
+                    (lambda (exn)
+                      (if (procedure? (exn:invalid-xexpr-code exn))
+                          #t
+                          (begin ((error-display-handler) (exn-message exn) exn)
+                                 #f)))))
+  
+  (define k-url?
+    string?)
+
+  (define response-generator?
+    (k-url? . -> . servlet-response?))
+  
+  (define url-transform?
+    (k-url? . -> . k-url?))
+  
+  (define expiration-handler?
+    (or/c false/c
+          (request? . -> . response?)))
+    
+  (define embed/url?
+    (((request? . -> . any/c)) (expiration-handler?) . opt-> . string?))
+  
+  (provide/contract
+   [servlet-response? contract?]
+   [xexpr/callback? (any/c . -> . boolean?)]
+   [response-generator? contract?]
+   [k-url? (any/c . -> . boolean?)]
+   [url-transform? contract?]
+   [expiration-handler? contract?]
+   [embed/url? contract?]))
\ No newline at end of file
diff --git a/collects/web-server/servlet.ss b/collects/web-server/servlet.ss
index e1291e25f4..ea72b2a768 100644
--- a/collects/web-server/servlet.ss
+++ b/collects/web-server/servlet.ss
@@ -7,35 +7,8 @@
            "private/servlet.ss"
            "private/url.ss"
            "servlet-helpers.ss"
-           "timer.ss"
-           "web-cells.ss")
-  
-  ;; CONTRACT HELPERS
-  (define servlet-response? any/c)
-  
-  (define (xexpr/callback? x)
-    (correct-xexpr? x 
-                    (lambda () #t)
-                    (lambda (exn)
-                      (if (procedure? (exn:invalid-xexpr-code exn))
-                          #t
-                          (begin ((error-display-handler) (exn-message exn) exn)
-                                 #f)))))
-  
-  (define response-generator?
-    (string? . -> . servlet-response?))
-  
-  (define url-transform?
-    (string? . -> . string?))
-  
-  (define expiration-handler?
-    (request? . -> . void?))
-  
-  (define (parameter/c c)
-    parameter?)
-  
-  (define embed/url?
-    (((request? . -> . any/c)) (expiration-handler?) . opt-> . string?))
+           "web-cells.ss"
+           "servlet-structs.ss")  
   
   ;; ************************************************************
   ;; HELPERS
@@ -52,10 +25,11 @@
   ;; Weak contracts: the input is checked in output-response, and a message is
   ;; sent directly to the client (Web browser) instead of the terminal/log.
   (provide/contract
-   [xexpr/callback? (any/c . -> . boolean?)]
    [xexpr/callback->xexpr (embed/url? xexpr/callback? . -> . xexpr?)]
-   [current-url-transform (parameter/c url-transform?)]
-   [current-servlet-continuation-expiration-handler (parameter/c expiration-handler?)]
+   ; XXX contract
+   [current-url-transform parameter?]
+   ; XXX contract
+   [current-servlet-continuation-expiration-handler parameter?]
    [redirect/get (-> request?)]
    [redirect/get/forget (-> request?)]
    [adjust-timeout! (number? . -> . void?)]
@@ -68,17 +42,18 @@
    [send/suspend/callback (xexpr/callback? . -> . any/c)])
   
   (require "url.ss")
-  (provide
-   (all-from "web-cells.ss")
-   (all-from "servlet-helpers.ss")
-   (all-from "url.ss"))
+  (provide (all-from "web-cells.ss")
+           (all-from "servlet-helpers.ss")
+           (all-from "url.ss")
+           (all-from "servlet-structs.ss"))
   
   ;; ************************************************************
   ;; EXPORTS
   
   ;; current-url-transform : string? -> string?
+  (define (default-url-transformer x) x)
   (define current-url-transform
-    (make-parameter identity))
+    (make-parameter default-url-transformer))
   
   ;; current-servlet-continuation-expiration-handler : request -> response
   (define current-servlet-continuation-expiration-handler
diff --git a/collects/web-server/sig.ss b/collects/web-server/sig.ss
index 926df5f83b..12d21d48f4 100644
--- a/collects/web-server/sig.ss
+++ b/collects/web-server/sig.ss
@@ -1,21 +1,12 @@
 (module sig mzscheme
   (require (lib "unitsig.ss"))
-  (provide 
-   dispatch-server^ dispatch-server-config^
+  (require "dispatch-server-sig.ss")
+  (provide ; XXX contract signature
    web-server^ servlet^ web-config^ web-config/pervasive^ web-config/local^)
 
-  (define-signature dispatch-server^
-    (serve
-     serve-ports
-     ; for environment:
-     server-loop))
   (define-signature web-server^
     ((open dispatch-server^)))
   
-  (define-signature dispatch-server-config^
-    (port listen-ip max-waiting initial-connection-timeout
-          read-request dispatch))
-  
   (define-signature servlet^
     (initial-request send/suspend send/finish send/back send/forward adjust-timeout!))
 
diff --git a/collects/web-server/timer.ss b/collects/web-server/timer.ss
index c0a7fce8e6..749680d422 100644
--- a/collects/web-server/timer.ss
+++ b/collects/web-server/timer.ss
@@ -1,11 +1,8 @@
 (module timer mzscheme
-  (require "timer-structs.ss")
   (require (lib "list.ss")
+           (lib "contract.ss")
            (lib "async-channel.ss"))
-  (provide timer? 
-           start-timer reset-timer! increment-timer!
-           cancel-timer!
-           start-timer-manager)
+  (require "timer-structs.ss")
   
   (define timer-ch (make-async-channel))
   
@@ -86,7 +83,15 @@
     (revise-timer! timer
                    (+ (- (timer-expire-seconds timer) (current-inexact-milliseconds))
                       (* 1000 secs))
-                   (timer-action timer))))
+                   (timer-action timer)))
+  
+  (provide/contract
+   [timer? (any/c . -> . boolean?)]
+   [start-timer-manager (custodian? . -> . void)]
+   [start-timer (number? (-> void) . -> . timer?)]
+   [reset-timer! (timer? number? . -> . void)]
+   [increment-timer! (timer? number? . -> . void)]
+   [cancel-timer! (timer? . -> . void)]))
 
 ; --- timeout plan
 
diff --git a/collects/web-server/url.ss b/collects/web-server/url.ss
index b7e27b6c1d..db49998e56 100644
--- a/collects/web-server/url.ss
+++ b/collects/web-server/url.ss
@@ -1,18 +1,12 @@
 (module url mzscheme
   (require (lib "list.ss")
            (lib "etc.ss")
+           (lib "contract.ss")
            (lib "url.ss" "net")
            (lib "struct.ss"))
   (require "private/url.ss"
            "request-structs.ss")
-           
-  ;; URL parsing
-  (provide (struct servlet-url (protocol host port servlets-root instance-id k-id nonce servlet-path extra-path))
-           servlet-url->url-string
-           servlet-url->url-string/no-continuation
-           servlet-url->servlet-url/no-extra-path 
-           request->servlet-url
-           uri->servlet-url)
+  
   (define-struct servlet-url (protocol host port
                                        servlets-root 
                                        instance-id k-id nonce 
@@ -38,17 +32,17 @@
   (define (servlet-url->url-string su)
     (let ([the-url
            (make-url (servlet-url-protocol su)
-                         #f
-                         #f ;(servlet-url-host su)
-                         #f ;(servlet-url-port su)
-                         #t
-                         (append (reverse (rest (reverse (servlet-url-servlets-root su))))
-                                 (list (make-path/param (path/param-path (first (reverse (servlet-url-servlets-root su))))
-                                                        empty))
-                                 (servlet-url-servlet-path su)
-                                 (servlet-url-extra-path su))
-                         empty
-                         #f)])
+                     #f
+                     #f ;(servlet-url-host su)
+                     #f ;(servlet-url-port su)
+                     #t
+                     (append (reverse (rest (reverse (servlet-url-servlets-root su))))
+                             (list (make-path/param (path/param-path (first (reverse (servlet-url-servlets-root su))))
+                                                    empty))
+                             (servlet-url-servlet-path su)
+                             (servlet-url-extra-path su))
+                     empty
+                     #f)])
       (if (and (servlet-url-instance-id su)
                (servlet-url-k-id su) 
                (servlet-url-nonce su))               
@@ -88,4 +82,22 @@
                           (list (first (url-path uri)))
                           k-instance k-id k-salt
                           servlet-path
-                          path)))))
+                          path))))
+  
+  (provide/contract
+   ; XXX contract maybe
+   [struct servlet-url ([protocol (or/c false/c string?)]
+                        [host (or/c false/c string?)]
+                        [port (or/c false/c natural-number/c)]
+                        [servlets-root (listof path/param?)]
+                        [instance-id number?]
+                        [k-id number?]
+                        [nonce number?]
+                        [servlet-path (listof path/param?)]
+                        [extra-path (listof path/param?)])]
+   [servlet-url->url-string (servlet-url? . -> . string?)]
+   [servlet-url->url-string/no-continuation (servlet-url? . -> . string?)]
+   [servlet-url->servlet-url/no-extra-path (servlet-url? . -> . servlet-url?)]
+   [request->servlet-url (request? . -> . servlet-url?)]
+   ; XXX contract maybe
+   [uri->servlet-url ((url?) ((or/c false/c string?) (or/c false/c natural-number/c)) . opt-> . servlet-url?)]))
\ No newline at end of file
diff --git a/collects/web-server/util.ss b/collects/web-server/util.ss
index 19ca24028d..51b8564d80 100644
--- a/collects/web-server/util.ss
+++ b/collects/web-server/util.ss
@@ -8,24 +8,6 @@
            (lib "uri-codec.ss" "net"))
   (require "request-structs.ss")
   
-  (provide provide-define-struct
-           extract-flag
-           translate-escapes
-           hash-table-empty?
-           url-path->string)
-  
-  (provide/contract
-   [valid-port? (any/c . -> . boolean?)]
-   [decompose-request ((request?) . ->* . (url? symbol? string?))]
-   [network-error ((symbol? string?) (listof any/c) . ->* . (void))]
-   [path->list  (path? . -> . (cons/c (or/c path? (symbols 'up 'same))
-                                      (listof (or/c path? (symbols 'up 'same)))))]
-   [url-path->path ((or/c (symbols 'up 'same) path?) string? . -> . path?)]
-   [directory-part (path? . -> . path?)]
-   [lowercase-symbol! ((or/c string? bytes?) . -> . symbol?)]
-   [exn->string ((or/c exn? any/c) . -> . string?)]
-   [build-path-unless-absolute (path? (or/c string? path?) . -> . path?)])
-  
   ;; valid-port? : any/c -> boolean?
   (define (valid-port? p)
     (and (number? p) (integer? p) (exact? p) (<= 1 p 65535)))
@@ -40,7 +22,7 @@
          [else (list* "/"
                       (maybe-join-params (car strs))
                       (loop (cdr strs)))]))))
-  
+    
   ;; needs to unquote things!
   (define (maybe-join-params s)
     (cond
@@ -89,7 +71,7 @@
   ;; Notes: (GregP)
   ;; 1. What's the significance of char # 255 ???
   ;; 2. 255 isn't an ascii character. ascii is 7-bit
-  ;; 3. OK fuck this. It is only used in three places, some of them
+  ;; 3. OK f this. It is only used in three places, some of them
   ;;    will involve bytes while the others may involve strings. So
   ;;    I will just use regular expressions and get on with life.
   (define (prefix?-old prefix)
@@ -152,20 +134,6 @@
                              [else (cons x acc)]))
                          null
                          (regexp-split #rx"/" p)))))))
-
-  ; update-params : Url (U #f String) -> String
-  ; to create a new url just like the old one, but with a different parameter part
-  ;; GREGP: this is broken! replace with the version from new-kernel
-  ;  (define (update-params uri params)
-  ;    (url->string
-  ;     (make-url (url-scheme uri)
-  ;               (url-user uri)
-  ;               (url-host uri)
-  ;               (url-port uri)
-  ;               (url-path uri)
-  ;               params
-  ;               (url-query uri)
-  ;               (url-fragment uri))))
   
   ; to convert a platform dependent path into a listof path parts such that
   ; (forall x (equal? (path->list x) (path->list (apply build-path (path->list x)))))
@@ -178,19 +146,9 @@
             [else ; conflate 'relative and #f
              new-acc])))))
   
-  ; this should go somewhere that other collections can use it too
-  (define-syntax provide-define-struct
-    (lambda (stx)
-      (syntax-case stx ()
-        [(_ (struct-name parent-name) (field ...))
-         (syntax (begin (define-struct (struct-name parent-name) (field ...))
-                        (provide (struct struct-name (field ...)))))]
-        [(_ struct-name (field ...))
-         (syntax (begin (define-struct struct-name (field ...))
-                        (provide (struct struct-name (field ...)))))])))
-  
   ; this is used by launchers
   ; extract-flag : sym (listof (cons sym alpha)) alpha -> alpha
+  ; XXX remove
   (define (extract-flag name flags default)
     (let ([x (assq name flags)])
       (if x
@@ -199,9 +157,7 @@
   
   ; hash-table-empty? : hash-table -> bool
   (define (hash-table-empty? table)
-    (let/ec out
-      (hash-table-for-each table (lambda (k v) (out #f)))
-      #t))
+    (zero? (hash-table-count table)))
   
   ; This comes from Shriram's collection, and should be exported form there.
   ; translate-escapes : String -> String
@@ -220,4 +176,20 @@
             (cond
               [(char=? ic #\+) #\space]
               [else ic]))
-          (list* c (loop cs))])))))
\ No newline at end of file
+          (list* c (loop cs))]))))
+  
+  (provide/contract
+   [url-path->string ((listof (or/c string? path/param?)) . -> . string?)]
+   [extract-flag (symbol? (listof (cons/c symbol? any/c)) any/c . -> . any/c)]
+   [translate-escapes (string? . -> . string?)]
+   [hash-table-empty? (any/c . -> . boolean?)]
+   [valid-port? (any/c . -> . boolean?)]
+   [decompose-request ((request?) . ->* . (url? symbol? string?))]
+   [network-error ((symbol? string?) (listof any/c) . ->* . (void))]
+   [path->list  (path? . -> . (cons/c (or/c path? (symbols 'up 'same))
+                                      (listof (or/c path? (symbols 'up 'same)))))]
+   [url-path->path ((or/c (symbols 'up 'same) path?) string? . -> . path?)]
+   [directory-part (path? . -> . path?)]
+   [lowercase-symbol! ((or/c string? bytes?) . -> . symbol?)]
+   [exn->string ((or/c exn? any/c) . -> . string?)]
+   [build-path-unless-absolute (path? (or/c string? path?) . -> . path?)]))
\ No newline at end of file
diff --git a/collects/web-server/web-cells.ss b/collects/web-server/web-cells.ss
index 6fc6accb2d..84c433d8a3 100644
--- a/collects/web-server/web-cells.ss
+++ b/collects/web-server/web-cells.ss
@@ -1,25 +1,25 @@
 (module web-cells mzscheme  
-  (require (lib "struct.ss"))
-
+  (require (lib "struct.ss")
+           (lib "contract.ss"))
+  
   (define-struct (exn:fail:frame:top exn) ())
   (define (exn:fail:frame:top-raise)
     (raise (make-exn:fail:frame:top
 	    "Reached top of stack"
 	    (current-continuation-marks))))
-  (provide exn:fail:frame:top?)
   
   ;; frames
   (define-struct frame ())
   (define-struct (frame:empty frame) ())
   ; frame:ns : (alist * (box frame) * namespace)
   (define-struct (frame:ns frame) (annotations boxed-parent namespace))
-
+  
   ; frame:ns?/raise : frame -> frame
   (define (frame:ns?/raise f)
     (if (frame:ns? f)
 	f
 	(exn:fail:frame:top-raise)))
-
+  
   ; make-frame/parent : (box frame) -> frame:ns
   (define (make-frame/parent parent-frame-box)
     (make-frame:ns (list) parent-frame-box (make-namespace 'empty)))
@@ -32,7 +32,7 @@
 	(search-frames (frame:ns?/raise
 			(unbox (frame:ns-boxed-parent a-frame)))
 		       predicate?)))
-
+  
   ; frame-ref : frame:ns symbol -> any
   ; Lookups up the variable in the frame and its parent(s)
   (define (frame-ref a-frame var)
@@ -47,12 +47,12 @@
   
   ; frame-set? : frame:ns symbol -> boolean
   (define (frame-set? a-frame var)
-   (not
-    (not 
-     (namespace-variable-value
-      var #f
-      (lambda () #f)
-      (frame:ns-namespace a-frame)))))
+    (not
+     (not 
+      (namespace-variable-value
+       var #f
+       (lambda () #f)
+       (frame:ns-namespace a-frame)))))
   
   ; frame-set! : frame:ns symbol any -> void
   ; Sets the variable in the frame to a value
@@ -60,12 +60,10 @@
     (namespace-set-variable-value! 
      var val
      #t (frame:ns-namespace a-frame)))
-      
-  ;; frame stacks
   
+  ;; frame stacks  
   (define *global-root-id* (gensym))
-  (define *session-root-id* (gensym))
-
+  
   ; *frame-stack* : (box frame)
   (define *frame-stack*
     (make-parameter
@@ -79,33 +77,18 @@
   ; global-root? : frame:ns -> boolean
   (define (global-root? a-frame)
     (annotation-present? *global-root-id* a-frame))
-  
-  ; session-root? : frame:ns -> boolean
-  (define (session-root? a-frame)
-    (annotation-present? *session-root-id* a-frame))
-  
+    
   ; make-frame/top : -> frame:ns
   (define (make-frame/top)
-    (let* ([cur-top-box (*frame-stack*)]
-	   [cur-top (unbox cur-top-box)])
-      (cond
-        #;[(not (frame:ns? cur-top))
-           ; Construct global
-           (copy-struct frame:ns (make-frame/parent cur-top-box)
-                        [frame:ns-annotations (list (cons *global-root-id* #t))])]
-        [(global-root? cur-top)
-         ; Construct session
-         (copy-struct frame:ns (make-frame/parent cur-top-box)
-                      [frame:ns-annotations (list (cons *session-root-id* #t))])]
-        [else
-         ; Construct normal
-         (make-frame/parent cur-top-box)])))
+    (define cur-top-box (*frame-stack*))
+    (define cur-top (unbox cur-top-box))
+    (make-frame/parent cur-top-box))
   
   ; push-frame! : -> void
   ; Pushs a new frame onto the session stack
   (define (push-frame!)
     (*frame-stack* (box (make-frame/top))))
-    
+  
   ; pop-frame! : -> void
   ; Pops the frame from the stack
   (define (pop-frame!)
@@ -114,10 +97,10 @@
   ; save-stack/push/return : (-> 'a) -> 'a
   ; Pushes a frame after the thunk's execution with the same parent as the call site
   (define (save-stack/push/return thunk)
-    (let ([initial-stack (*frame-stack*)])
-      (begin0 (thunk)
-              (*frame-stack* initial-stack)
-              (push-frame!))))
+    (define initial-stack (*frame-stack*))
+    (begin0 (thunk)
+            (*frame-stack* initial-stack)
+            (push-frame!)))
   
   ; syntax version of above
   (define-syntax with-frame-after
@@ -143,106 +126,42 @@
   
   ; cells
   (define-struct cell (id))
-  (define-struct (cell:global cell) ())
-  (define-struct (cell:session cell) ())
   (define-struct (cell:local cell) ())
   
+  (define web-cell:local? cell:local?)
+  
   ; ext:make-'a 'b -> 'a
-  (define (ext:make-cell:global default)
-    (let ([new-name (gensym)])
-      (frame-set! (search-stack global-root?)
-		  new-name default)
-      (make-cell:global new-name)))
-  (define (ext:make-cell:session default)
-    (let ([new-name (gensym)])
-      (frame-set! (search-stack global-root?)
-                new-name default)
-      (make-cell:session new-name)))
-  (define (ext:make-cell:local default)
-    (let ([new-name (gensym)])
-      (frame-set! (search-stack global-root?)
-                  new-name default)
-      (make-cell:local new-name)))
-      
-  ; cell:global-ref : cell:global -> any
-  ; returns the value of the global cell
-  (define (cell:global-ref gc)
-    (frame-ref (search-stack global-root?)
-               (cell-id gc)))
-  ; cell:global-set! : cell:global any -> void
-  ; sets the value of the global cell
-  (define (cell:global-set! gc nv)
+  (define (make-web-cell:local default)
+    (define new-name (gensym))
     (frame-set! (search-stack global-root?)
-                (cell-id gc)
-                nv))
-  
-  ; cell:session-ref : cell:session -> any
-  ; returns the value of the session cell
-  (define (cell:session-ref sc)
-    (frame-ref (search-stack session-root?)
-               (cell-id sc)))
-  ; cell:session-set! : cell:session any -> void
-  ; sets the value of the session cell
-  (define (cell:session-set! sc nv)
-    (frame-set! (search-stack session-root?)
-                (cell-id sc)
-                nv))
-  
+                new-name default)
+    (make-cell:local new-name))
+    
   ; cell:local-ref : cell:local -> any
   ; returns the value of the local cell
-  (define (cell:local-ref lc)
+  (define (web-cell:local-ref lc)
     (frame-ref (search-stack frame?)
                (cell-id lc)))
   ; cell:local-set! : cell:local any -> void
   ; sets the value of the local cell at the last place it was set, including the default
-  (define (cell:local-set! lc nv)
+  (define (web-cell:local-set! lc nv)
     (frame-set! (search-stack
                  (lambda (f) (frame-set? f (cell-id lc))))
                 (cell-id lc)
                 nv))
   ; cell:local-mask : cell:local any -> void
   ; masks the local cell to the given value
-  (define (cell:local-mask lc nv)
+  (define (web-cell:local-mask lc nv)
     (frame-set! (search-stack frame?)
                 (cell-id lc)
                 nv))
-  
-  ; cell-ref : cell -> any
-  (define (cell-ref c)
-    (cond 
-      [(cell:global? c) (cell:global-ref c)]
-      [(cell:session? c) (cell:session-ref c)]
-      [(cell:local? c) (cell:local-ref c)]))
-  
-;  ;; linking parameters to cells
-;  (define *parameter-links* (ext:make-cell:session (list)))
-;  (define-struct parameter-link (parameter cell))
-;  
-;  ; link-parameter : parameter cell -> void
-;  (define (link-parameter p c)
-;    (cell:session-set! *parameter-links*
-;                       (cons (make-parameter-link p c)
-;                             (cell:session-ref *parameter-links*))))
-;  
-;  ; reinstall-linked-parameters : -> void
-;  (define (reinstall-linked-parameters)
-;    (for-each (lambda (link)
-;                ((parameter-link-parameter link)
-;                 (cell-ref (parameter-link-cell link))))
-;              (cell:session-ref *parameter-links*)))
-   
-  (provide with-frame
-           with-frame-after
-           (rename cell:global? web-cell:global?)
-           (rename ext:make-cell:global make-web-cell:global)
-           (rename cell:global-ref web-cell:global-ref)
-           (rename cell:global-set! web-cell:global-set!)
-           (rename cell:session? web-cell:session?)
-           (rename ext:make-cell:session make-web-cell:session)
-           (rename cell:session-ref web-cell:session-ref)
-           (rename cell:session-set! web-cell:session-set!)
-           (rename cell:local? web-cell:local?)
-           (rename ext:make-cell:local make-web-cell:local)
-           (rename cell:local-ref web-cell:local-ref)
-           (rename cell:local-set! web-cell:local-set!)
-           (rename cell:local-mask web-cell:local-mask)))
\ No newline at end of file
+    
+  (provide with-frame ; syntax
+           with-frame-after)
+  (provide/contract
+   [exn:fail:frame:top? (any/c . -> . boolean?)]
+   [web-cell:local? (any/c . -> . boolean?)]
+   [make-web-cell:local (any/c . -> . web-cell:local?)]
+   [web-cell:local-ref (web-cell:local? . -> . any/c)]
+   [web-cell:local-set! (web-cell:local? any/c . -> . void)]
+   [web-cell:local-mask (web-cell:local? any/c . -> . void)]))
\ No newline at end of file
diff --git a/collects/web-server/web-server-structs.ss b/collects/web-server/web-server-structs.ss
index 64939d7ca8..61f9526e23 100644
--- a/collects/web-server/web-server-structs.ss
+++ b/collects/web-server/web-server-structs.ss
@@ -1,9 +1,14 @@
 (module web-server-structs mzscheme
-  (provide (all-defined))
+  (require (lib "contract.ss"))
+  (require "contract.ss")
   
   (define current-server-custodian (make-parameter #f))
+  (provide current-server-custodian) ; parameter
   
   ;; make-servlet-custodian: -> custodian
   ;; create a custodian for the dynamic extent of a servlet continuation
   (define (make-servlet-custodian)
-    (make-custodian (current-server-custodian))))
\ No newline at end of file
+    (make-custodian (current-server-custodian)))
+  
+  (provide/contract
+   [make-servlet-custodian (-> custodian?)]))
\ No newline at end of file
diff --git a/collects/web-server/web-server-unit.ss b/collects/web-server/web-server-unit.ss
index 71f298b20f..36e575c253 100644
--- a/collects/web-server/web-server-unit.ss
+++ b/collects/web-server/web-server-unit.ss
@@ -1,9 +1,12 @@
 (module web-server-unit mzscheme
+  (require (lib "tcp-sig.ss" "net")
+           (lib "contract.ss")
+           (lib "unitsig.ss"))
   (require "sig.ss"
+           "dispatch-server-unit.ss"
+           "dispatch-server-sig.ss"
            "web-server-structs.ss"
-           "connection-manager.ss"
            "configuration-structures.ss"
-           "servlet.ss"
            "private/cache-table.ss"
            (rename "private/request.ss" 
                    the-read-request read-request))
@@ -13,107 +16,11 @@
            (prefix servlets: "dispatchers/dispatch-servlets.ss")
            (prefix path-procedure: "dispatchers/dispatch-pathprocedure.ss")
            (prefix log: "dispatchers/dispatch-log.ss")
-           (prefix host: "dispatchers/dispatch-host.ss"))
-  (require (lib "tcp-sig.ss" "net")
-           (lib "unitsig.ss")
-           (lib "string.ss")
-           (lib "list.ss")
-           (lib "url.ss" "net"))
-  
-  (provide web-server@)  
-  
-  ;; ****************************************  
-  (define dispatch-server@
-    (unit/sig dispatch-server^
-      (import net:tcp^ (config : dispatch-server-config^))
-      
-      ;; serve: -> -> void
-      ;; start the server and return a thunk to shut it down
-      (define (serve)
-        (define the-server-custodian (make-custodian))
-        (start-connection-manager the-server-custodian)
-        (parameterize ([current-custodian the-server-custodian]
-                       [current-server-custodian the-server-custodian]
-                       [current-thread-initial-stack-size 3])
-          (thread
-           (lambda ()
-             (start-listener))))
-        (lambda ()
-          (custodian-shutdown-all the-server-custodian)))
-      
-      ;; start-listener : -> void
-      ;; loops around starting a listener if the current listener dies
-      (define (start-listener)
-        (define listener 
-          (tcp-listen config:port config:max-waiting
-                      #t config:listen-ip))
-        (define get-ports
-          (lambda () (tcp-accept listener)))
-        (with-handlers ([void (lambda (e)
-                                ; If the exception did not kill the listener
-                                (with-handlers ([void void])
-                                  (tcp-close listener))
-                                ; Rethrow the error to this thread's error printer
-                                (raise e))])
-          (server-loop get-ports
-                       tcp-addresses)))
-      
-      ;; server-loop: (-> input-port output-port) (input-port -> string string) -> void
-      ;; start a thread to handle each incoming connection
-      (define (server-loop get-ports port-addresses)
-        (let loop ()
-          (define connection-cust (make-custodian))
-          (parameterize ([current-custodian connection-cust])
-            (define-values (ip op) (get-ports))
-            (serve-ports/inner ip op
-                               port-addresses))
-          (loop)))
-      
-      ;; serve-ports : input-port output-port -> void
-      ;; returns immediately, spawning a thread to handle
-      ;; the connection
-      ;; NOTE: (GregP) should allow the user to pass in a connection-custodian
-      (define (serve-ports ip op)
-        (define server-cust (make-custodian))
-        (start-connection-manager server-cust)
-        (parameterize ([current-custodian server-cust]
-                       [current-server-custodian server-cust])
-          (define connection-cust (make-custodian))
-          (parameterize ([current-custodian connection-cust])
-            (serve-ports/inner ip op
-                               (lambda (ip)
-                                 (values "127.0.0.1"
-                                         "127.0.0.1"))))))
-      
-      ;; serve-ports/inner : input-port output-port (input-port -> string string) -> void
-      ;; returns immediately, spawning a thread to handle
-      (define (serve-ports/inner ip op port-addresses)
-        (thread
-         (lambda ()
-           (define conn
-             (new-connection config:initial-connection-timeout
-                             ip op (current-custodian) #f))
-           (with-handlers ([exn:fail:network?
-                            (lambda (e)
-                              (kill-connection! conn)
-                              (raise e))])
-             (serve-connection conn port-addresses)))))
-      
-      ;; serve-connection: connection (input-port -> string string) -> void
-      ;; respond to all requests on this connection
-      (define (serve-connection conn port-addresses)
-        (let connection-loop ()
-          (define-values (req close?) (config:read-request conn config:port port-addresses))
-          (unless close?
-            (set-connection-close?! conn #f))
-          (adjust-connection-timeout! conn config:initial-connection-timeout)
-          (config:dispatch conn req)
-          (when close?
-            (set-connection-close?! conn #t))
-          (cond
-            [(connection-close? conn) (kill-connection! conn)]
-            [else (connection-loop)])))))
-  
+           (prefix host: "dispatchers/dispatch-host.ss"))  
+  (provide/contract
+   ; XXX contract
+   [web-server@ unit/sig?])  
+    
   (define web-config@->dispatch-server-config@
     (unit/sig dispatch-server-config^
       (import (config : web-config^))
diff --git a/collects/web-server/web-server.ss b/collects/web-server/web-server.ss
index 6ac4b335d3..6d4133e09e 100644
--- a/collects/web-server/web-server.ss
+++ b/collects/web-server/web-server.ss
@@ -1,10 +1,15 @@
 (module web-server mzscheme
   (require (lib "tcp-sig.ss" "net")
            (lib "unitsig.ss")
+           (lib "contract.ss")
            "sig.ss"
            "web-server-unit.ss"
-	   "configuration.ss")
-  (provide serve)
+	   "configuration.ss"
+           "configuration-structures.ss")
+  (provide/contract
+   [serve (case-> [configuration? . -> . (-> void?)]
+                  [configuration? natural-number/c . -> . (-> void?)]
+                  [configuration? natural-number/c string? . -> . (-> void?)])])
   
   ; : configuration [nat] [(U str #f)] -> -> void
   (define serve
@@ -29,6 +34,4 @@
                    (serve))
                  s)])
        (export))
-     net:tcp^))
-
-)
\ No newline at end of file
+     net:tcp^)))
\ No newline at end of file
diff --git a/collects/web-server/xexpr-callback.ss b/collects/web-server/xexpr-callback.ss
deleted file mode 100644
index 8f32b7182d..0000000000
--- a/collects/web-server/xexpr-callback.ss
+++ /dev/null
@@ -1,17 +0,0 @@
-;; Mike Burns 2004
-
-;; Used for send/suspend/callback.
-
-(module xexpr-callback mzscheme
-  (require (lib "xml.ss" "xml"))
-  (provide xexpr/callback?)
-
-  ;; Is it a Xexpr, or an Xexpr with procedures?
-  (define (xexpr/callback? x)
-    (correct-xexpr? x 
-                    (lambda () #t)
-                    (lambda (exn)
-                      (if (procedure? (exn:invalid-xexpr-code exn))
-                          #t
-                          (begin ((error-display-handler) (exn-message exn) exn)
-                                  #f))))))