diff --git a/pkgs/drracket-pkgs/drracket/drracket/private/main.rkt b/pkgs/drracket-pkgs/drracket/drracket/private/main.rkt
index a16540a340..e64cbc298b 100644
--- a/pkgs/drracket-pkgs/drracket/drracket/private/main.rkt
+++ b/pkgs/drracket-pkgs/drracket/drracket/private/main.rkt
@@ -580,49 +580,6 @@
   
   (preferences:set-default 'drracket:show-killed-dialog #t boolean?)
   
-  (drr:set-default 'drracket:multi-file-search:recur? #t boolean?)
-  (drr:set-default 'drracket:multi-file-search:filter? #t boolean?)
-  (drr:set-default 'drracket:multi-file-search:filter-regexp "\\.(rkt.?|scrbl|ss|scm)$" string?)
-  (drr:set-default 'drracket:multi-file-search:search-string "" string?)
-  (drr:set-default 'drracket:multi-file-search:search-type
-                           1
-                           (λ (x) 
-                             (and (number? x)
-                                  (exact? x)
-                                  (integer? x)
-                                  (<= 0 x)
-                                  (< x (length drracket:multi-file-search:search-types)))))
-  
-  ;; drracket:mult-file-search:search-check-boxes : (listof (listof boolean))
-  (drr:set-default 'drracket:multi-file-search:search-check-boxes 
-                           (map (λ (x) (map cdr (drracket:multi-file-search:search-type-params x)))
-                                drracket:multi-file-search:search-types)
-                           (λ (x) 
-                             (and (list? x)
-                                  (andmap (λ (x)
-                                            (and (list? x)
-                                                 (andmap boolean? x)))
-                                          x))))
-  
-  (drr:set-default 'drracket:multi-file-search:percentages
-                           '(1/3 2/3)
-                           (λ (x) (and (list? x)
-                                       (= 2 (length x))
-                                       (= 1 (apply + x)))))
-  
-  (drr:set-default 'drracket:multi-file-search:frame-size '(300 . 400) 
-                           (λ (x) (and (pair? x)
-                                       (number? (car x))
-                                       (number? (cdr x)))))
-  (drr:set-default 'drracket:multi-file-search:directories 
-                   '()
-                   (lambda (x) (and (list? x) (andmap string? x))))
-  (drr:set-default 'drracket:multi-file-search:directory 
-                           ;; The default is #f because
-                           ;; filesystem-root-list is expensive under Windows
-                           #f 
-                           (lambda (x) (or (not x) (string? x))))
-
   
   (drr:set-default 'drracket:large-letters-font #f (λ (x)
                                                        (or (and (pair? x)
diff --git a/pkgs/drracket-pkgs/drracket/drracket/private/multi-file-search.rkt b/pkgs/drracket-pkgs/drracket/drracket/private/multi-file-search.rkt
index 10067c39be..6feecfaa45 100644
--- a/pkgs/drracket-pkgs/drracket/drracket/private/multi-file-search.rkt
+++ b/pkgs/drracket-pkgs/drracket/drracket/private/multi-file-search.rkt
@@ -1,20 +1,61 @@
-#lang racket/unit
-  (require framework
-           mzlib/class
-           mred
-           racket/file
-           racket/path
-           racket/list
-           mzlib/thread
-           mzlib/async-channel
-           string-constants
-           drracket/private/drsig)
-  
+#lang racket/base
+
+(require framework
+         racket/class
+         racket/contract
+         racket/unit
+         racket/path
+         racket/list
+         racket/gui/base
+         mzlib/async-channel
+         string-constants
+         drracket/private/drsig
+         mrlib/close-icon
+         "get-module-path.rkt")
+
+(define sc-browse-collections "Browse\nCollections")
+(define sc-add-another-directory "Add Another Directory")
+
+(provide multi-file-search@)
+
+;; search-type = (make-search-type string make-searcher (listof (cons string boolean)))
+;; the param strings are the labels for checkboxes
+;; the param booleans are the default values for the checkboxes
+;; these are the available searches
+(define-struct search-type (label make-searcher params) #:transparent)
+
+;; search-info = (make-search-info (listof string) boolean (union #f regexp) search-type string)
+;; the search-string field is only informative; not used for actual searching
+(define-struct search-info (dirs recur? filter searcher search-string) #:transparent)
+
+;; search-types : (listof search-type)
+(define search-types
+  (list (make-search-type
+         (string-constant mfs-string-match/graphics)
+         (λ (info search-string) (exact-match-searcher info search-string))
+         (list (cons (string-constant mfs-case-sensitive-label) #f)))
+        (make-search-type
+         (string-constant mfs-regexp-match/no-graphics)
+         (λ (info search-string) (regexp-match-searcher info search-string))
+         (list))))
+
+;; search-entry = (make-search-entry string string number number number)
+(define-struct search-entry (base-dir filename line-string line-number col-number match-length) 
+  #:transparent)
+
+;; to make these available to be defined in the unit with the right names.
+(define _search-types search-types)
+(define _search-type-params search-type-params)
+
+(define-unit multi-file-search@
   (import [prefix drracket:frame: drracket:frame^]
           [prefix drracket:unit: drracket:unit^]
           [prefix drracket: drracket:interface^])
   (export drracket:multi-file-search^)
   
+  (define search-type-params _search-type-params)
+  (define search-types _search-types)
+  
   ;; multi-file-search : -> void
   ;; opens a dialog to configure the search and initiates the search
   (define (multi-file-search)
@@ -28,31 +69,6 @@
   ;; the second argument is called for each match.
   ;;     the arguments are: line-string line-number col-number match-length
   
-  
-  ;; search-type = (make-search-type string make-searcher (listof (cons string boolean)))
-  ;; the param strings are the labels for checkboxes
-  ;; the param booleans are the default values for the checkboxes
-  ;; these are the available searches
-  (define-struct search-type (label make-searcher params))
-  
-  ;; search-info = (make-search-info string boolean (union #f regexp) search-type string)
-  ;; the search-string field is only informative; not used for actual searching
-  (define-struct search-info (dir recur? filter searcher search-string))
-  
-  ;; search-types : (listof search-type)
-  (define search-types
-    (list (make-search-type
-           (string-constant mfs-string-match/graphics)
-           (λ (info search-string) (exact-match-searcher info search-string))
-           (list (cons (string-constant mfs-case-sensitive-label) #f)))
-          (make-search-type
-           (string-constant mfs-regexp-match/no-graphics)
-           (λ (info search-string) (regexp-match-searcher info search-string))
-           (list))))
-  
-  ;; search-entry = (make-search-entry string number number number)
-  (define-struct search-entry (filename line-string line-number col-number match-length))
-  
   ;; open-search-window : search-info -> void
   ;; thread: eventspace main thread
   ;; opens a window and creates the thread that does the search
@@ -65,7 +81,10 @@
                            (gui-utils:trim-string (search-info-search-string search-info)
                                                   (- 200 (string-length fmt-s)))))]))
     (define panel (make-object saved-vertical-resizable% (send frame get-area-container)))
-    (define button-panel (make-object horizontal-panel% (send frame get-area-container)))
+    (define button-panel (new horizontal-panel%
+                              [parent (send frame get-area-container)]
+                              [alignment '(right center)]
+                              [stretchable-height #f]))
     (define open-button (make-object button% (string-constant mfs-open-file) button-panel
                           (λ (x y) (open-file-callback))))
     (define stop-button (make-object button% (string-constant mfs-stop-search) button-panel
@@ -104,8 +123,6 @@
     (send results-text lock #t)
     (send frame reflow-container)
     (send panel set-percentages (preferences:get 'drracket:multi-file-search:percentages))
-    (send button-panel set-alignment 'right 'center)
-    (send button-panel stretchable-height #f)
     (send frame show #t)
     
     (let loop ()
@@ -119,7 +136,7 @@
            (send results-text search-interrupted)]
           [else
            (send results-text add-match
-                 (search-info-dir search-info)
+                 (search-entry-base-dir match)
                  (search-entry-filename match)
                  (search-entry-line-string match)
                  (search-entry-line-number match)
@@ -220,67 +237,65 @@
                              col-in-current-file)])
                 (send t set-position pos)))))]
       
-      [define/public add-match
-        (λ (base-filename full-filename line-string line-number col-number match-length)
-          (lock #f)
-          (let* ([new-line-position (last-position)]
-                 [short-filename 
-                  (path->string
-                   (find-relative-path 
-                    (normalize-path base-filename)
-                    (normalize-path full-filename)))]
-                 [this-match-number (last-paragraph)]
-                 [len (string-length short-filename)]
-                 [insertion-start #f]
-                 [show-this-match
-                  (λ ()
-                    (set! match-shown? #t)
-                    (set! current-file full-filename)
-                    (set! line-in-current-file line-number)
-                    (set! col-in-current-file col-number)
-                    (set-position new-line-position new-line-position)
-                    (send zoom-text begin-edit-sequence)
-                    (send zoom-text lock #f)
-                    (unless (really-same-file? full-filename (send zoom-text get-filename))
-                      (send zoom-text load-file/gui-error full-filename))
-                    (send zoom-text set-position (send zoom-text paragraph-start-position line-number))
-                    (let ([start (+ (send zoom-text paragraph-start-position line-number)
-                                    col-number)])
-                      (send zoom-text change-style match-delta start (+ start match-length)))
-                    (send zoom-text lock #t)
-                    (send zoom-text set-caret-owner #f 'global)
-                    (hilite-line this-match-number)
-                    (send zoom-text end-edit-sequence))])
-            (unless match-shown?
-              (erase))
-            (unless widest-filename
-              (set! widest-filename len))
-            (if (<= len widest-filename)
-                (begin
-                  (set! insertion-start (last-position))
-                  (insert (make-string (- widest-filename len) #\space) 
-                          (last-position) (last-position)))
-                (begin
-                  (indent-all-lines (- len widest-filename))
-                  (set! insertion-start (last-position))
-                  (set! widest-filename len)))
-            (let ([filename-start (last-position)])
-              (insert short-filename (last-position) (last-position))
-              (insert ": " (last-position) (last-position))
-              (change-style filename-delta insertion-start (last-position))
-              (let ([line-start (last-position)])
-                (insert line-string (last-position) (last-position))
-                (change-style match-delta
-                              (+ line-start col-number)
-                              (+ line-start col-number match-length)))
-              (set-clickback filename-start (last-position)
-                             (λ (_1 _2 _3)
-                               (show-this-match)))
-              (insert #\newline (last-position) (last-position))
-              
-              (unless match-shown?
-                (show-this-match))))
-          (lock #t))]
+      (define/public (add-match base-filename full-filename line-string line col match-length)
+        (lock #f)
+        (define new-line-position (last-position))
+        (define short-filename 
+          (path->string
+           (find-relative-path 
+            (normalize-path base-filename)
+            (normalize-path full-filename))))
+        (define this-match-number (last-paragraph))
+        (define len (string-length short-filename))
+        (define insertion-start #f)
+        (define (show-this-match)
+          (set! match-shown? #t)
+          (set! current-file full-filename)
+          (set! line-in-current-file line)
+          (set! col-in-current-file col)
+          (set-position new-line-position new-line-position)
+          (send zoom-text begin-edit-sequence)
+          (send zoom-text lock #f)
+          (unless (really-same-file? full-filename (send zoom-text get-filename))
+            (send zoom-text load-file/gui-error full-filename))
+          (send zoom-text set-position (send zoom-text paragraph-start-position line))
+          (let ([start (+ (send zoom-text paragraph-start-position line)
+                          col)])
+            (send zoom-text change-style match-delta start (+ start match-length)))
+          (send zoom-text lock #t)
+          (send zoom-text set-caret-owner #f 'global)
+          (hilite-line this-match-number)
+          (send zoom-text end-edit-sequence))
+        (unless match-shown?
+          (erase))
+        (unless widest-filename
+          (set! widest-filename len))
+        (if (<= len widest-filename)
+            (begin
+              (set! insertion-start (last-position))
+              (insert (make-string (- widest-filename len) #\space) 
+                      (last-position) (last-position)))
+            (begin
+              (indent-all-lines (- len widest-filename))
+              (set! insertion-start (last-position))
+              (set! widest-filename len)))
+        (let ([filename-start (last-position)])
+          (insert short-filename (last-position) (last-position))
+          (insert ": " (last-position) (last-position))
+          (change-style filename-delta insertion-start (last-position))
+          (let ([line-start (last-position)])
+            (insert line-string (last-position) (last-position))
+            (change-style match-delta
+                          (+ line-start col)
+                          (+ line-start col match-length)))
+          (set-clickback filename-start (last-position)
+                         (λ (_1 _2 _3)
+                           (show-this-match)))
+          (insert #\newline (last-position) (last-position))
+          
+          (unless match-shown?
+            (show-this-match)))
+        (lock #t))
       
       (define/public (search-interrupted)
         (lock #f)
@@ -296,7 +311,7 @@
           (lock #t)))
       
       (inherit get-style-list set-style-list set-styles-sticky)
-      (super-instantiate ())
+      (super-new)
       (send zoom-text lock #t)
       (set-styles-sticky #f)
       (insert (string-constant mfs-searching...))))
@@ -324,7 +339,7 @@
         (when on?
           (send frame set-text-to-search (get-editor)))
         (super on-focus on?))
-      (super-instantiate ())))
+      (super-new)))
   
   ;; thread: eventspace main thread
   (define search-size-frame%
@@ -336,10 +351,9 @@
         (preferences:set 'drracket:multi-file-search:frame-size (cons w h))
         (super on-size w h))
       (let ([size (preferences:get 'drracket:multi-file-search:frame-size)])
-        (super-instantiate ()
-          (label name)
-          (width (car size))
-          (height (cdr size))))))
+        (super-new [label name]
+                   [width (car size)]
+                   [height (cdr size)]))))
   
   
   ;; this vertical-resizable class just remembers the percentage between the
@@ -353,246 +367,20 @@
           (when (= (length ps) 2)
             (preferences:set 'drracket:multi-file-search:percentages ps)))
         (inner (void) after-percentage-change))
-      (super-instantiate ())))
-  
-  ;; configure-search : -> (union #f search-info)
-  ;; thread: eventspace main thread
-  ;; configures the search
-  (define (configure-search)
-    (keymap:call/text-keymap-initializer
-     (λ ()
-       (define dialog (make-object dialog% (string-constant mfs-configure-search)
-                        #f 500 #f #f #f '(resize-border)))
-       (define outer-files-panel (make-object vertical-panel% dialog '(border)))
-       (define outer-method-panel (make-object vertical-panel% dialog '(border)))
-       (define button-panel (make-object horizontal-panel% dialog))
-       (define files-label (make-object message% (string-constant mfs-files-section) outer-files-panel))
-       (define files-inset-outer-panel (make-object horizontal-panel% outer-files-panel))
-       (define files-inset-panel (make-object horizontal-panel% files-inset-outer-panel))
-       (define files-panel (make-object vertical-panel% files-inset-outer-panel))
-       (define method-label (make-object message% (string-constant mfs-search-section) outer-method-panel))
-       (define method-inset-outer-panel (make-object horizontal-panel% outer-method-panel))
-       (define method-inset-panel (make-object horizontal-panel% method-inset-outer-panel))
-       (define method-panel (make-object vertical-panel% method-inset-outer-panel))
-       
-       (define dir-panel (make-object horizontal-panel% files-panel))
-       (define dir-field 
-         (new combo-field%
-              [parent dir-panel] 
-              [label (string-constant mfs-dir)] 
-              [choices (preferences:get 'drracket:multi-file-search:directories)]
-              [stretchable-width #t] 
-              [stretchable-height #f]
-              [callback (λ (x y) (dir-field-callback))]))
-
-       (define dir-button (make-object button% (string-constant browse...) dir-panel 
-                            (λ (x y) (dir-button-callback))))
-       
-       (define recur-check-box (make-object check-box% (string-constant mfs-recur-over-subdirectories) files-panel
-                                 (λ (x y) (recur-check-box-callback))))
-       
-       (define filter-panel (make-object horizontal-panel% files-panel))
-       (define filter-check-box (make-object check-box% (string-constant mfs-regexp-filename-filter) filter-panel
-                                  (λ (x y) (filter-check-box-callback))))
-       (define filter-text-field (make-object text-field% #f filter-panel 
-                                   (λ (x y) (filter-text-field-callback))))
-       
-       (define methods-choice (make-object choice% #f (map search-type-label search-types) method-panel 
-                                (λ (x y) (methods-choice-callback))))
-       (define search-text-field (make-object text-field% (string-constant mfs-search-string) method-panel
-                                   (λ (x y) (search-text-field-callback))))
-       (define active-method-panel (make-object panel:single% method-panel))
-       (define methods-check-boxess
-         (let ([pref (preferences:get 'drracket:multi-file-search:search-check-boxes)])
-           (map
-            (λ (search-type prefs-settings)
-              (let ([p (make-object vertical-panel% active-method-panel)]
-                    [params (search-type-params search-type)])
-                (send p set-alignment 'left 'center)
-                (map (λ (flag-pair prefs-setting)
-                       (let ([cb (make-object check-box% 
-                                   (car flag-pair)
-                                   p
-                                   (λ (evt chk) (method-callback chk)))])
-                         (send cb set-value prefs-setting)
-                         cb))
-                     params
-                     (if (= (length params) (length prefs-settings))
-                         prefs-settings
-                         (map (λ (x) #f) params)))))
-            search-types
-            (if (= (length search-types) (length pref))
-                pref
-                (map (λ (x) '()) search-types)))))
-       (define-values (ok-button cancel-button)
-         (gui-utils:ok/cancel-buttons
-          button-panel
-          (λ (x y) (ok-button-callback))
-          (λ (x y) (cancel-button-callback))))
-       (define spacer (make-object grow-box-spacer-pane% button-panel))
-       
-       ;; initialized to a searcher during the ok button callback
-       ;; so the user can be informed of an error before the dialog
-       ;; closes.
-       (define searcher #f)
-       
-       ;; initialized to a regexp if the user wants to filter filenames,
-       ;; during the ok-button-callback, so errors can be signaled.
-       (define filter #f)
-       
-       ;; title for message box that signals error messages
-       (define message-box-title (string-constant mfs-drscheme-multi-file-search))
-       
-       (define (ok-button-callback)
-         (cond
-           [(with-handlers ([exn:fail:filesystem?
-                             (λ (x) #f)])
-              (directory-exists? (send dir-field get-value)))
-            
-            (let ([df (send dir-field get-value)])
-              (when (path-string? df)
-                (define new-l (cons df (remove df (preferences:get 'drracket:multi-file-search:directories))))
-                (preferences:set 'drracket:multi-file-search:directories
-                                 (take new-l (min (length new-l) 10)))))
-            
-            (let ([_searcher
-                   ((search-type-make-searcher (list-ref search-types (send methods-choice get-selection)))
-                    (map (λ (cb) (send cb get-value))
-                         (send (send active-method-panel active-child) get-children))
-                    (send search-text-field get-value))])
-              (if (string? _searcher)
-                  (message-box message-box-title _searcher dialog)
-                  (let ([regexp (with-handlers ([(λ (x) #t)
-                                                 (λ (exn)
-                                                   (format "~a" (exn-message exn)))])
-                                  (and (send filter-check-box get-value)
-                                       (regexp (send filter-text-field get-value))))])
-                    (if (string? regexp)
-                        (message-box message-box-title regexp dialog)
-                        (begin (set! searcher _searcher)
-                               (set! filter regexp)
-                               (set! ok? #t)
-                               (send dialog show #f))))))]
-           [else
-            (message-box message-box-title
-                         (format (string-constant mfs-not-a-dir) (send dir-field get-value))
-                         dialog)]))
-       (define (cancel-button-callback)
-         (send dialog show #f))
-       
-       (define (method-callback chk)
-         (preferences:set
-          'drracket:multi-file-search:search-check-boxes
-          (let loop ([methods-check-boxess methods-check-boxess])
-            (cond
-              [(null? methods-check-boxess) null]
-              [else
-               (cons (let loop ([methods-check-boxes (car methods-check-boxess)])
-                       (cond
-                         [(null? methods-check-boxes) null]
-                         [else (cons (send (car methods-check-boxes) get-value)
-                                     (loop (cdr methods-check-boxes)))]))
-                     (loop (cdr methods-check-boxess)))]))))
-       
-       (define (dir-field-callback)
-         (let ([df (send dir-field get-value)])
-           (when (path-string? df)
-             (preferences:set 'drracket:multi-file-search:directory df))))
-       
-       (define (filter-check-box-callback) 
-         (preferences:set 'drracket:multi-file-search:filter? (send filter-check-box get-value))
-         (send filter-text-field enable (send filter-check-box get-value)))
-       (define (filter-text-field-callback)
-         (preferences:set 'drracket:multi-file-search:filter-regexp (send filter-text-field get-value)))
-       
-       (define (recur-check-box-callback)
-         (preferences:set 'drracket:multi-file-search:recur? (send recur-check-box get-value)))
-       (define (methods-choice-callback)
-         (define which (send methods-choice get-selection))
-         (preferences:set 'drracket:multi-file-search:search-type which) 
-         (set-method which))
-       (define (set-method which)
-         (send active-method-panel active-child
-               (list-ref (send active-method-panel get-children)
-                         which)))
-       (define (search-text-field-callback)
-         (preferences:set 'drracket:multi-file-search:search-string (send search-text-field get-value)))
-       (define (dir-button-callback) 
-         (define old-d (string->path (send dir-field get-value)))
-         (define new-d (get-directory #f 
-                                      #f 
-                                      (and (directory-exists? old-d)
-                                           old-d)))
-         (when (and new-d
-                    (directory-exists? new-d))
-           (define str (path->string new-d))
-           (preferences:set 'drracket:multi-file-search:directory str)
-           (send dir-field set-value str)))
-       
-       (define (get-files)
-         (let ([dir (string->path (send dir-field get-value))])
-           (and (directory-exists? dir)
-                (if (send recur-check-box get-value)
-                    (build-recursive-file-list dir filter)
-                    (build-flat-file-list dir filter)))))
-       
-       (define ok? #f)
-       
-       (send button-panel set-alignment 'right 'center)
-       (send dir-panel stretchable-height #f)
-       (send outer-files-panel stretchable-height #f)
-       (send outer-files-panel set-alignment 'left 'center)
-       (send files-inset-panel min-width 20)
-       (send files-inset-panel stretchable-width #f)
-       (send files-panel set-alignment 'left 'center)
-       
-       (send recur-check-box set-value (preferences:get 'drracket:multi-file-search:recur?))
-       (send filter-check-box set-value (preferences:get 'drracket:multi-file-search:filter?))
-       (send search-text-field set-value (preferences:get 'drracket:multi-file-search:search-string))
-       (send filter-text-field set-value (preferences:get 'drracket:multi-file-search:filter-regexp))
-       (send dir-field set-value (let ([p (preferences:get 'drracket:multi-file-search:directory)])
-                                   (or p
-                                       (let ([p (path->string (car (filesystem-root-list)))])
-                                         (preferences:set 'drracket:multi-file-search:directory p)
-                                         p))))
-       
-       (send outer-method-panel stretchable-height #f)
-       (send outer-method-panel set-alignment 'left 'center)
-       (send method-inset-panel min-width 20)
-       (send method-inset-panel stretchable-width #f)
-       (send method-panel set-alignment 'left 'center)
-       (send filter-panel stretchable-height #f)
-       
-       (send methods-choice set-selection (preferences:get 'drracket:multi-file-search:search-type))
-       (set-method (preferences:get 'drracket:multi-file-search:search-type)) 
-       
-       (send search-text-field focus)
-       (let ([t (send search-text-field get-editor)])
-         (send t set-position 0 (send t last-position)))
-       (send dialog show #t)
-       
-       (and
-        ok?
-        (make-search-info
-         (send dir-field get-value)
-         (send recur-check-box get-value)
-         (and (send filter-check-box get-value)
-              (regexp (send filter-text-field get-value)))
-         searcher
-         (send search-text-field get-value))))))
+      (super-new)))
   
   
   ;; do-search : search-info text -> void
   ;; thread: searching thread
   ;; called in a new thread that may be broken (to indicate a stop)
   (define (do-search search-info channel)
-    (let* ([dir (search-info-dir search-info)]
-           [filter (search-info-filter search-info)]
-           [searcher (search-info-searcher search-info)]
-           [get-filenames (if (search-info-recur? search-info)
-                              (build-recursive-file-list dir filter)
-                              (build-flat-file-list dir filter))])
-      (with-handlers ([exn:break? (λ (x) (async-channel-put channel 'break))])
+    (define filter (search-info-filter search-info))
+    (define searcher (search-info-searcher search-info))
+    (with-handlers ([exn:break? (λ (x) (async-channel-put channel 'break))])
+      (for ([dir (in-list (search-info-dirs search-info))])
+        (define get-filenames (if (search-info-recur? search-info)
+                                  (build-recursive-file-list dir filter)
+                                  (build-flat-file-list dir filter)))
         (let loop ()
           (let ([filename (get-filenames)])
             (when filename
@@ -601,13 +389,14 @@
                           (async-channel-put
                            channel
                            (make-search-entry
+                            dir
                             filename
                             line-string
                             line-number
                             col-number
                             match-length))))
-              (loop))))
-        (async-channel-put channel 'done))))
+              (loop)))))
+      (async-channel-put channel 'done)))
   
   ;; build-recursive-file-list : string (union regexp #f) -> (-> (union string #f))
   ;; thread: search thread
@@ -667,49 +456,417 @@
                (set! contents (cdr contents)))]
             [else
              (set! contents (cdr contents))
-             (loop)])))))
-  
-  ;; exact-match-searcher : make-searcher
-  (define (exact-match-searcher params key)        ;; thread: main eventspace thread
-    (let ([case-sensitive? (car params)])
-      (λ (filename add-entry)                 ;; thread: searching thread
-        (let ([text (make-object text:line-spacing%)])
-          (send text load-file filename)
-          (let loop ([pos 0])
-            (let ([found (send text find-string key 'forward pos 'eof #t case-sensitive?)])
-              (when found
-                (let* ([para (send text position-paragraph found)]
-                       [para-start (send text paragraph-start-position para)]
-                       [line-string (send text get-text para-start
-                                          (send text paragraph-end-position para))]
-                       [line-number para]
-                       [col-number (- found para-start)]
-                       [match-length (string-length key)])
-                  (add-entry line-string line-number col-number match-length)
-                  (loop (+ found 1))))))))))
-  
-  ;; regexp-match-searcher : make-searcher
-  ;; thread: searching thread
-  (define (regexp-match-searcher parmas key)       ;; thread: main eventspace thread
-    (let ([re:key (with-handlers ([(λ (x) #t)
-                                   (λ (exn)
-                                     (format "~a" (exn-message exn)))])
-                    (regexp key))])
-      (if (string? re:key)
-          re:key
-          (λ (filename add-entry)             ;; thread: searching thread
-            (call-with-input-file filename
-              (λ (port)
-                (let loop ([line-number 0])
-                  (let ([line (read-line port)])
-                    (cond
-                      [(eof-object? line) (void)]
-                      [else
-                       (let ([match (regexp-match-positions re:key line)])
-                         (when match
-                           (let ([pos (car match)])
-                             (add-entry line line-number 
-                                        (car pos)
-                                        (- (cdr pos) (car pos))))))
-                       (loop (+ line-number 1))]))))
-              #:mode 'text)))))
+             (loop)]))))))
+
+;; configure-search : -> (union #f search-info)
+;; thread: eventspace main thread
+;; configures the search
+(define (configure-search)
+  (keymap:call/text-keymap-initializer
+   (λ ()
+     (define dialog (new dialog%
+                         [label (string-constant mfs-configure-search)]
+                         [width 500]
+                         [style '(resize-border)]
+                         [stretchable-height #f]))
+     (define outer-files-panel (make-object vertical-panel% dialog '(border)))
+     (define outer-method-panel (make-object vertical-panel% dialog '(border)))
+     (define button-panel (new horizontal-panel% 
+                               [parent dialog]
+                               [alignment '(right center)]
+                               [stretchable-height #f]))
+     (define files-label (make-object message% (string-constant mfs-files-section) 
+                           outer-files-panel))
+     (define files-inset-outer-panel (make-object horizontal-panel% outer-files-panel))
+     (define files-inset-panel (make-object horizontal-panel% files-inset-outer-panel))
+     (define files-panel (make-object vertical-panel% files-inset-outer-panel))
+     (define method-label (make-object message% (string-constant mfs-search-section) 
+                            outer-method-panel))
+     (define method-inset-outer-panel (make-object horizontal-panel% outer-method-panel))
+     (define method-inset-panel (make-object horizontal-panel% method-inset-outer-panel))
+     (define method-panel (make-object vertical-panel% method-inset-outer-panel))
+     
+     (define multi-dir+browse-collections-panel (new horizontal-panel% 
+                                                     [alignment '(center top)]
+                                                     [stretchable-height #f]
+                                                     [parent files-panel]))
+     (define multi-dir-panel (new vertical-panel% [parent multi-dir+browse-collections-panel]))
+     (define dir-fields '())
+     (define (add-a-dir-field init-value)
+       (send dialog begin-container-sequence)
+       (define need-to-add-closers? (and (pair? dir-fields) (null? (cdr dir-fields))))
+       (define dir-panel (new horizontal-panel%
+                              [parent multi-dir-panel]
+                              [stretchable-height #f]))
+       (define dir-field
+         (new combo-field%
+              [parent dir-panel] 
+              [label (string-constant mfs-dir)] 
+              [choices (preferences:get 'drracket:multi-file-search:directories)]
+              [init-value init-value]
+              [stretchable-width #t] 
+              [stretchable-height #f]
+              [callback (λ (x y) (update-directory-prefs))]))
+     
+       (define dir-button (new button% 
+                               [label (string-constant browse...)]
+                               [parent dir-panel]
+                               [callback (λ (x y) (dir-button-callback))]))
+       (define (dir-button-callback) 
+         (define old-d (string->path (send dir-field get-value)))
+         (define new-d (get-directory #f 
+                                      #f 
+                                      (and (directory-exists? old-d)
+                                           old-d)))
+         (when (and new-d
+                    (directory-exists? new-d))
+           (define str (path->string new-d))
+           (send dir-field set-value str)
+           (update-directory-prefs)))
+       (set! dir-fields (cons dir-field dir-fields))
+       (update-directory-prefs)
+       (cond
+         [(null? (cdr dir-fields))
+          ;; len=1 : add to none of them
+          (void)]
+         [(null? (cddr dir-fields))
+          ;; len=2 : add to all of them
+          (for ([dir-panel (in-list (send multi-dir-panel get-children))])
+            (add-a-closer dir-panel))]
+         [else
+          ;; len>2 : add to this one
+          (add-a-closer dir-panel)])
+       (send dialog end-container-sequence))
+       
+     (define (add-a-closer dir-panel)
+       (define ci
+         (new close-icon%
+              [parent dir-panel]
+              [callback
+               (λ () (remove-a-dir-panel dir-panel))]))
+       (send dir-panel change-children
+             (λ (l)
+               (append (remove ci l) (list ci)))))
+     
+     (define (remove-a-dir-panel dir-panel)
+       (define dir-field (for/or ([child (in-list (send dir-panel get-children))])
+                           (and (is-a? child combo-field%)
+                                child)))
+       (set! dir-fields (remove dir-field dir-fields))
+       (send multi-dir-panel change-children (λ (l) (remove dir-panel l)))
+       (update-directory-prefs)
+       (when (and (pair? dir-fields)
+                  (null? (cdr dir-fields)))
+         ;; only one dir field left, get rid of the close-icon
+         (let loop ([parent multi-dir-panel])
+           (for ([child (in-list (send parent get-children))])
+             (cond
+               [(is-a? child close-icon%) 
+                (send parent change-children (λ (l) (remove child l)))]
+               [(is-a? child area-container<%>) (loop child)])))))
+     
+     (define (update-directory-prefs)
+       (define new-pref
+         (for/list ([dir-field (in-list dir-fields)])
+           (define dfv (send dir-field get-value))
+           (and (path-string? dfv) dfv)))
+       (when (andmap values new-pref)
+         (preferences:set 'drracket:multi-file-search:directory new-pref)))
+     
+     (define browse-collections-button 
+       (new button%
+            [label sc-browse-collections]
+            [parent multi-dir+browse-collections-panel]
+            [callback (λ (x y) 
+                        (define paths (get-module-path-from-user #:dir? #t))
+                        (when paths
+                          (define delta-dirs (- (length dir-fields) (length paths)))
+                          (cond
+                            [(< delta-dirs 0)
+                             (for ([x (in-range (- delta-dirs))])
+                               (add-a-dir-field ""))]
+                            [(> delta-dirs 0)
+                             (for ([x (in-range delta-dirs)]
+                                   [dir-field (in-list (send multi-dir-panel get-children))])
+                               (remove-a-dir-panel dir-field))])
+                          (for ([path (in-list paths)]
+                                [dir-field (in-list dir-fields)])
+                            (send dir-field set-value (path->string path)))
+                          (update-directory-prefs)))]))
+     (define recur+another-parent (new horizontal-panel%
+                                       [parent files-panel]
+                                       [stretchable-height #f]))
+     (define recur-check-box (new check-box% 
+                                  [label (string-constant mfs-recur-over-subdirectories)]
+                                  [parent recur+another-parent]
+                                  [callback (λ (x y) (recur-check-box-callback))]))
+     (new horizontal-panel% [parent recur+another-parent]) ;; spacer
+     (define another-dir-button (new button%
+                                     [label sc-add-another-directory]
+                                     [parent recur+another-parent]
+                                     [callback (λ (x y) (add-a-dir-field ""))]))
+     
+     (define filter-panel (make-object horizontal-panel% files-panel))
+     (define filter-check-box (make-object check-box% 
+                                (string-constant mfs-regexp-filename-filter) 
+                                filter-panel
+                                (λ (x y) (filter-check-box-callback))))
+     (define filter-text-field (make-object text-field% #f filter-panel 
+                                 (λ (x y) (filter-text-field-callback))))
+     
+     (define methods-choice (make-object choice%
+                              #f (map search-type-label search-types) method-panel 
+                              (λ (x y) (methods-choice-callback))))
+     (define search-text-field (make-object text-field% 
+                                 (string-constant mfs-search-string) method-panel
+                                 (λ (x y) (search-text-field-callback))))
+     (define active-method-panel (make-object panel:single% method-panel))
+     (define methods-check-boxess
+       (let ([pref (preferences:get 'drracket:multi-file-search:search-check-boxes)])
+         (map
+          (λ (search-type prefs-settings)
+            (let ([p (make-object vertical-panel% active-method-panel)]
+                  [params (search-type-params search-type)])
+              (send p set-alignment 'left 'center)
+              (map (λ (flag-pair prefs-setting)
+                     (let ([cb (make-object check-box% 
+                                 (car flag-pair)
+                                 p
+                                 (λ (evt chk) (method-callback chk)))])
+                       (send cb set-value prefs-setting)
+                       cb))
+                   params
+                   (if (= (length params) (length prefs-settings))
+                       prefs-settings
+                       (map (λ (x) #f) params)))))
+          search-types
+          (if (= (length search-types) (length pref))
+              pref
+              (map (λ (x) '()) search-types)))))
+     (define-values (ok-button cancel-button)
+       (gui-utils:ok/cancel-buttons
+        button-panel
+        (λ (x y) (ok-button-callback))
+        (λ (x y) (cancel-button-callback))))
+     (define spacer (make-object grow-box-spacer-pane% button-panel))
+     
+     ;; initialized to a searcher during the ok button callback
+     ;; so the user can be informed of an error before the dialog
+     ;; closes.
+     (define searcher #f)
+     
+     ;; initialized to a regexp if the user wants to filter filenames,
+     ;; during the ok-button-callback, so errors can be signaled.
+     (define filter #f)
+     
+     ;; title for message box that signals error messages
+     (define message-box-title (string-constant mfs-drscheme-multi-file-search))
+     
+     (define (ok-button-callback)
+       (define dirs (for/list ([df (in-list dir-fields)])
+                      (send df get-value)))
+       (define dont-exist
+         (for/list ([dir (in-list dirs)]
+                    #:unless 
+                    (with-handlers ([exn:fail:filesystem? (λ (x) #f)])
+                      (and (path-string? dir)
+                           (directory-exists? dir))))
+           dir))
+         
+       (cond
+         [(null? dont-exist)
+          (define new-l (append dirs
+                                (remove* dirs
+                                         (preferences:get
+                                          'drracket:multi-file-search:directories))))
+          (preferences:set 'drracket:multi-file-search:directories
+                           (take new-l (min (length new-l) 10)))
+          
+          (define _searcher
+            ((search-type-make-searcher (list-ref search-types (send methods-choice get-selection)))
+             (map (λ (cb) (send cb get-value))
+                  (send (send active-method-panel active-child) get-children))
+             (send search-text-field get-value)))
+          (if (string? _searcher)
+              (message-box message-box-title _searcher dialog)
+              (let ([regexp (with-handlers ([(λ (x) #t)
+                                             (λ (exn)
+                                               (format "~a" (exn-message exn)))])
+                              (and (send filter-check-box get-value)
+                                   (regexp (send filter-text-field get-value))))])
+                (if (string? regexp)
+                    (message-box message-box-title regexp dialog)
+                    (begin (set! searcher _searcher)
+                           (set! filter regexp)
+                           (set! ok? #t)
+                           (send dialog show #f)))))]
+         [else
+          (message-box message-box-title
+                       (format (string-constant mfs-not-a-dir)
+                               (car dont-exist))
+                       dialog)]))
+     (define (cancel-button-callback)
+       (send dialog show #f))
+     
+     (define (method-callback chk)
+       (preferences:set
+        'drracket:multi-file-search:search-check-boxes
+        (let loop ([methods-check-boxess methods-check-boxess])
+          (cond
+            [(null? methods-check-boxess) null]
+            [else
+             (cons (let loop ([methods-check-boxes (car methods-check-boxess)])
+                     (cond
+                       [(null? methods-check-boxes) null]
+                       [else (cons (send (car methods-check-boxes) get-value)
+                                   (loop (cdr methods-check-boxes)))]))
+                   (loop (cdr methods-check-boxess)))]))))
+     
+     (define (filter-check-box-callback) 
+       (preferences:set 'drracket:multi-file-search:filter? (send filter-check-box get-value))
+       (send filter-text-field enable (send filter-check-box get-value)))
+     (define (filter-text-field-callback)
+       (preferences:set 'drracket:multi-file-search:filter-regexp
+                        (send filter-text-field get-value)))
+     
+     (define (recur-check-box-callback)
+       (preferences:set 'drracket:multi-file-search:recur? (send recur-check-box get-value)))
+     (define (methods-choice-callback)
+       (define which (send methods-choice get-selection))
+       (preferences:set 'drracket:multi-file-search:search-type which) 
+       (set-method which))
+     (define (set-method which)
+       (send active-method-panel active-child
+             (list-ref (send active-method-panel get-children)
+                       which)))
+     (define (search-text-field-callback)
+       (preferences:set 'drracket:multi-file-search:search-string
+                        (send search-text-field get-value)))
+     
+     (define ok? #f)
+     
+     (send outer-files-panel stretchable-height #f)
+     (send outer-files-panel set-alignment 'left 'center)
+     (send files-inset-panel min-width 20)
+     (send files-inset-panel stretchable-width #f)
+     (send files-panel set-alignment 'left 'center)
+     
+     (send recur-check-box set-value (preferences:get 'drracket:multi-file-search:recur?))
+     (send filter-check-box set-value (preferences:get 'drracket:multi-file-search:filter?))
+     (send search-text-field set-value (preferences:get 'drracket:multi-file-search:search-string))
+     (send filter-text-field set-value (preferences:get 'drracket:multi-file-search:filter-regexp))
+     (for ([pth/f (in-list (preferences:get 'drracket:multi-file-search:directory))])
+       (define pth (or pth/f (path->string (car (filesystem-root-list)))))
+       (add-a-dir-field pth))
+     
+     (send outer-method-panel stretchable-height #f)
+     (send outer-method-panel set-alignment 'left 'center)
+     (send method-inset-panel min-width 20)
+     (send method-inset-panel stretchable-width #f)
+     (send method-panel set-alignment 'left 'center)
+     (send filter-panel stretchable-height #f)
+     
+     (send methods-choice set-selection (preferences:get 'drracket:multi-file-search:search-type))
+     (set-method (preferences:get 'drracket:multi-file-search:search-type)) 
+     
+     (send search-text-field focus)
+     (let ([t (send search-text-field get-editor)])
+       (send t set-position 0 (send t last-position)))
+     (send dialog show #t)
+     
+     (and
+      ok?
+      (make-search-info
+       (for/list ([dir-field (in-list dir-fields)])
+         (send dir-field get-value))
+       (send recur-check-box get-value)
+       (and (send filter-check-box get-value)
+            (regexp (send filter-text-field get-value)))
+       searcher
+       (send search-text-field get-value))))))
+
+
+
+
+
+;; exact-match-searcher : make-searcher
+(define (exact-match-searcher params key)        ;; thread: main eventspace thread
+  (let ([case-sensitive? (car params)])
+    (λ (filename add-entry)                 ;; thread: searching thread
+      (let ([text (make-object text:line-spacing%)])
+        (send text load-file filename)
+        (let loop ([pos 0])
+          (let ([found (send text find-string key 'forward pos 'eof #t case-sensitive?)])
+            (when found
+              (let* ([para (send text position-paragraph found)]
+                     [para-start (send text paragraph-start-position para)]
+                     [line-string (send text get-text para-start
+                                        (send text paragraph-end-position para))]
+                     [line-number para]
+                     [col-number (- found para-start)]
+                     [match-length (string-length key)])
+                (add-entry line-string line-number col-number match-length)
+                (loop (+ found 1))))))))))
+
+;; regexp-match-searcher : make-searcher
+;; thread: searching thread
+(define (regexp-match-searcher parmas key)       ;; thread: main eventspace thread
+  (let ([re:key (with-handlers ([(λ (x) #t)
+                                 (λ (exn)
+                                   (format "~a" (exn-message exn)))])
+                  (regexp key))])
+    (if (string? re:key)
+        re:key
+        (λ (filename add-entry)             ;; thread: searching thread
+          (call-with-input-file filename
+            (λ (port)
+              (let loop ([line-number 0])
+                (let ([line (read-line port)])
+                  (cond
+                    [(eof-object? line) (void)]
+                    [else
+                     (let ([match (regexp-match-positions re:key line)])
+                       (when match
+                         (let ([pos (car match)])
+                           (add-entry line line-number 
+                                      (car pos)
+                                      (- (cdr pos) (car pos))))))
+                     (loop (+ line-number 1))]))))
+            #:mode 'text)))))
+
+
+(preferences:set-default 'drracket:multi-file-search:directories 
+                         '()
+                         (lambda (x) (and (list? x) (andmap string? x))))
+;; drracket:mult-file-search:search-check-boxes : (listof (listof boolean))
+(preferences:set-default 'drracket:multi-file-search:search-check-boxes 
+                         (map (λ (x) (map cdr (search-type-params x))) search-types)
+                         (listof (listof boolean?)))
+(preferences:set-default 'drracket:multi-file-search:recur? #t boolean?)
+(preferences:set-default 'drracket:multi-file-search:filter? #t boolean?)
+(preferences:set-default 'drracket:multi-file-search:filter-regexp
+                         "\\.(rkt[^~]?|scrbl|ss|scm)$" string?)
+(preferences:set-default 'drracket:multi-file-search:search-string "" string?)
+(preferences:set-default 'drracket:multi-file-search:search-type
+                         1
+                         (λ (x) 
+                           (and (exact-nonnegative-integer? x)
+                                (< x (length search-types)))))
+
+(preferences:set-default 'drracket:multi-file-search:percentages
+                         '(1/3 2/3)
+                         (and/c (listof (between/c 0 1))
+                                (λ (x) (= 1 (apply + x)))))
+
+(preferences:set-default 'drracket:multi-file-search:frame-size '(300 . 400) 
+                         (cons/c dimension-integer? dimension-integer?))
+(preferences:set-default 'drracket:multi-file-search:directory 
+                         ;; #f means the filesystem root, but that's
+                         ;; expensive to compute under windows so we
+                         ;; delay the computation until the dialog
+                         ;; is opened.
+                         '(#f)
+                         (non-empty-listof (or/c #f (and/c string? path-string?))))
+
+
+(module+ main (configure-search))