diff --git a/library/bootstrap/boot-stage2.factor b/library/bootstrap/boot-stage2.factor
index 0ddf5d0065..322b1e30ed 100644
--- a/library/bootstrap/boot-stage2.factor
+++ b/library/bootstrap/boot-stage2.factor
@@ -88,6 +88,7 @@ cpu "x86" = "mini" get not and [
     "/library/tools/jedit-wire.factor"
     "/library/tools/profiler.factor"
     "/library/tools/walker.factor"
+    "/library/tools/annotations.factor"
     "/library/tools/jedit.factor"
     "/library/bootstrap/image.factor"
 
@@ -125,6 +126,11 @@ cpu "x86" = "mini" get not and [
     "/library/ui/gestures.factor"
     "/library/ui/hand.factor"
     "/library/ui/layouts.factor"
+    "/library/ui/piles.factor"
+    "/library/ui/shelves.factor"
+    "/library/ui/borders.factor"
+    "/library/ui/stacks.factor"
+    "/library/ui/frames.factor"
     "/library/ui/world.factor"
     "/library/ui/labels.factor"
     "/library/ui/buttons.factor"
diff --git a/library/test/interpreter.factor b/library/test/interpreter.factor
index 0924f70211..b080790279 100644
--- a/library/test/interpreter.factor
+++ b/library/test/interpreter.factor
@@ -9,6 +9,12 @@ USE: math-internals
 USE: lists
 USE: kernel
 
+: interpret ( quot -- )
+    #! The quotation is called with each word as its executed.
+    done? [ drop ] [ [ next swap call ] keep interpret ] ifte ;
+
+: run ( -- ) [ do ] interpret ;
+
 : test-interpreter
     init-interpreter meta-cf set run meta-d get ;
 
diff --git a/library/tools/annotations.factor b/library/tools/annotations.factor
new file mode 100644
index 0000000000..8602d8baad
--- /dev/null
+++ b/library/tools/annotations.factor
@@ -0,0 +1,26 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
+IN: words
+
+! The annotation words let you flag a word for either tracing
+! or single-stepping. Note that currently, words referring to
+! annotated words cannot be compiled; and annotating a word has
+! no effect of compiled calls to that word.
+USING: interpreter kernel lists stdio strings ;
+
+: annotate ( word quot -- ) #! Quotation: ( word def -- def )
+    over [ word-def swap call ] keep set-word-def ;
+
+: (watch) >r "==> " swap word-name cat2 \ print r> cons cons ;
+
+: watch ( word -- )
+    #! Cause a message to be printed out when the word is
+    #! executed. To undo the effect of this, reload the
+    #! word with \ foo reload.
+    [ (watch) ] annotate ;
+
+: (break) [ walk ] cons ;
+
+: break ( word -- )
+    #! Cause the word to start the code walker when executed.
+    [ nip (break) ] annotate ;
diff --git a/library/tools/interpreter.factor b/library/tools/interpreter.factor
index 953426518c..e9f8ff1af9 100644
--- a/library/tools/interpreter.factor
+++ b/library/tools/interpreter.factor
@@ -5,7 +5,7 @@ USING: errors kernel lists math namespaces prettyprint stdio
 strings vectors words ;
 
 ! A Factor interpreter written in Factor. Used by compiler for
-! partial evaluation, also for trace and step.
+! partial evaluation, also by the walker.
 
 ! Meta-stacks
 SYMBOL: meta-r
@@ -36,15 +36,11 @@ SYMBOL: meta-cf
     meta-n [ ] change
     meta-c [ ] change ;
 
-: done-cf? ( -- ? )
-    meta-cf get not ;
-
-: done? ( -- ? )
-    done-cf? meta-r get vector-length 0 = and ;
+: done-cf? ( -- ? ) meta-cf get not ;
+: done? ( -- ? ) done-cf? meta-r get vector-length 0 = and ;
 
 ! Callframe.
-: up ( -- )
-    pop-r meta-cf set ;
+: up ( -- ) pop-r meta-cf set ;
 
 : next ( -- obj )
     meta-cf get [ meta-cf [ uncons ] change ] [ up next ] ifte ;
@@ -68,23 +64,14 @@ SYMBOL: meta-cf
         dup compound? [ word-def meta-call ] [ host-word ] ifte
     ] ?ifte ;
 
-: do ( obj -- )
-    dup word? [ meta-word ] [ push-d ] ifte ;
+: do ( obj -- ) dup word? [ meta-word ] [ push-d ] ifte ;
 
 : meta-word-1 ( word -- )
     dup "meta-word" word-prop [ call ] [ host-word ] ?ifte ;
 
-: do-1 ( obj -- )
-    dup word? [ meta-word-1 ] [ push-d ] ifte ;
+: do-1 ( obj -- ) dup word? [ meta-word-1 ] [ push-d ] ifte ;
 
-: interpret ( quot -- )
-    #! The quotation is called with each word as its executed.
-    done? [ drop ] [ [ next swap call ] keep interpret ] ifte ;
-
-: run ( -- ) [ do ] interpret ;
-
-: set-meta-word ( word quot -- )
-    "meta-word" set-word-prop ;
+: set-meta-word ( word quot -- ) "meta-word" set-word-prop ;
 
 \ datastack [ meta-d get clone push-d ] set-meta-word
 \ set-datastack [ pop-d clone meta-d set ] set-meta-word
@@ -99,3 +86,5 @@ SYMBOL: meta-cf
 \ call [ pop-d meta-call ] set-meta-word
 \ execute [ pop-d meta-word ] set-meta-word
 \ ifte [ pop-d pop-d pop-d [ nip ] [ drop ] ifte meta-call ] set-meta-word
+
+FORGET: set-meta-word
diff --git a/library/tools/walker.factor b/library/tools/walker.factor
index 5521d5fdfb..db551c72d8 100644
--- a/library/tools/walker.factor
+++ b/library/tools/walker.factor
@@ -4,8 +4,6 @@ IN: interpreter
 USING: errors kernel listener lists math namespaces prettyprint
 stdio strings vectors words ;
 
-! Some useful tools
-
 : &s
     #! Print stepper data stack.
     meta-d get {.} ;
@@ -23,7 +21,7 @@ stdio strings vectors words ;
     meta-c get [.] ;
 
 : &get ( var -- value )
-    #! Print stepper variable value.
+    #! Get stepper variable value.
     meta-n get (get) ;
 
 : stack-report ( -- )
@@ -41,7 +39,7 @@ stdio strings vectors words ;
     stack-report meta-cf get . ;
 
 : step
-    #! Step into current word.
+    #! Step over current word.
     [ next do-1 report ] not-done ;
 
 : into
@@ -49,23 +47,23 @@ stdio strings vectors words ;
     [ next do report ] not-done ;
 
 : walk-banner ( -- )
-    "The following words control the single-stepper:" print
     [ &s &r &n &c ] [ prettyprint-word " " write ] each
     "show stepper stacks." print
     \ &get prettyprint-word
     " ( var -- value ) inspects the stepper namestack." print
     \ step prettyprint-word " -- single step over" print
     \ into prettyprint-word " -- single step into" print
-    \ run prettyprint-word " -- run until end" print
     \ exit prettyprint-word " -- exit single-stepper" print
     report ;
 
+: walk-listener walk-banner "walk" listener-prompt set listener ;
+
 : walk ( quot -- )
     #! Single-step through execution of a quotation.
     [
-        "walk" listener-prompt set
         init-interpreter
         meta-cf set
-        walk-banner
-        listener
-    ] with-scope ;
+        datastack meta-d set
+        walk-listener
+        meta-d get
+    ] with-scope set-datastack ;
diff --git a/library/ui/borders.factor b/library/ui/borders.factor
new file mode 100644
index 0000000000..d1f3c2cf4f
--- /dev/null
+++ b/library/ui/borders.factor
@@ -0,0 +1,41 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
+IN: gadgets
+USING: errors generic hashtables kernel lists math namespaces
+sdl ;
+
+! A border lays out its children on top of each other, all with
+! a 5-pixel padding.
+TUPLE: border size ;
+
+C: border ( child delegate size -- border )
+    [ set-border-size ] keep
+    [ set-delegate ] keep
+    [ over [ add-gadget ] [ 2drop ] ifte ] keep ;
+
+: empty-border ( child -- border )
+    <empty-gadget> 5 <border> ;
+
+: line-border ( child -- border )
+    0 0 0 0 <etched-rect> <gadget> 5 <border> ;
+
+: filled-border ( child -- border )
+    0 0 0 0 <plain-rect> <gadget> 5 <border> ;
+
+: gadget-child gadget-children car ;
+
+: layout-border-x/y ( border -- )
+    dup border-size dup rot gadget-child move-gadget ;
+
+: layout-border-w/h ( border -- )
+    [ border-size 2 * ] keep
+    [ shape-w over - ] keep
+    [ shape-h rot - ] keep
+    gadget-child resize-gadget ;
+
+M: border pref-size ( border -- w h )
+    [ border-size 2 * ] keep
+    gadget-child pref-size >r over + r> rot + ;
+
+M: border layout* ( border -- )
+    dup layout-border-x/y layout-border-w/h ;
diff --git a/library/ui/editors.factor b/library/ui/editors.factor
index 6028900d6e..d6efe915fa 100644
--- a/library/ui/editors.factor
+++ b/library/ui/editors.factor
@@ -86,7 +86,8 @@ C: editor ( text -- )
     1 swap shape-h ;
 
 M: editor user-input* ( ch field -- ? )
-    [ insert-char ] with-editor t ;
+    [ [ insert-char ] with-editor ] keep
+    [ scroll>bottom ] swap handle-gesture drop  t ;
 
 M: editor layout* ( field -- )
     dup [ editor-text shape-size ] keep resize-gadget
diff --git a/library/ui/frames.factor b/library/ui/frames.factor
new file mode 100644
index 0000000000..a2ea457fff
--- /dev/null
+++ b/library/ui/frames.factor
@@ -0,0 +1,41 @@
+USING: gadgets kernel lists math namespaces sdl ;
+
+! A frame arranges left/right/top/bottom gadgets around a
+! center gadget, which gets any leftover space.
+TUPLE: frame gap left right top bottom center ;
+
+C: frame ( gap center -- frame )
+    [ set-frame-gap ] keep
+    [ set-frame-center ] keep
+    [ <empty-gadget> swap set-frame-left ] keep
+    [ <empty-gadget> swap set-frame-right ] keep
+    [ <empty-gadget> swap set-frame-top ] keep
+    [ <empty-gadget> swap set-frame-bottom ] keep ;
+
+: frame-major ( glue -- list )
+    [
+        dup frame-top , dup frame-center , frame-bottom ,
+    ] make-list ;
+
+: frame-minor ( glue -- list )
+    [
+        dup frame-left , dup frame-center , frame-right ,
+    ] make-list ;
+
+: max-h pref-size nip height [ max ] change ;
+: max-w pref-size drop width [ max ] change ;
+
+: add-h pref-size nip height [ + ] change ;
+: add-w pref-size drop width [ + ] change ;
+
+M: frame pref-size ( glue -- w h )
+    [
+        dup frame-major [ max-w ] each
+        dup frame-minor [ max-h ] each
+        dup frame-left add-w
+        dup frame-right add-w
+        dup frame-top add-h
+        dup frame-bottom add-h
+    ] with-pref-size ;
+
+
diff --git a/library/ui/layouts.factor b/library/ui/layouts.factor
index b753f1c695..e7772745eb 100644
--- a/library/ui/layouts.factor
+++ b/library/ui/layouts.factor
@@ -28,138 +28,3 @@ sdl ;
     [ 0 x set 0 y set call ] with-scope ; inline
 
 : default-gap 3 ;
-
-! A pile is a box that lays out its contents vertically.
-TUPLE: pile align gap fill ;
-
-C: pile ( align gap fill -- pile )
-    #! align: 0 left aligns, 1/2 center, 1 right.
-    #! gap: between each child.
-    #! fill: 0 leaves default width, 1 fills to pile width.
-    [ <empty-gadget> swap set-delegate ] keep
-    [ set-pile-fill ] keep
-    [ set-pile-gap ] keep
-    [ set-pile-align ] keep ;
-
-: <default-pile> 1/2 default-gap 0 <pile> ;
-: <line-pile> 0 0 1 <pile> ;
-
-M: pile pref-size ( pile -- w h )
-    [
-        dup pile-gap swap gadget-children
-        [ length 1 - 0 max * height set ] keep
-        [
-            pref-size
-            height [ + ] change
-            width [ max ] change
-        ] each
-    ] with-pref-size ;
-
-: w- swap shape-w swap pref-size drop - ;
-: pile-x/y ( pile gadget offset -- )
-    rot pile-align * >fixnum y get rot move-gadget ;
-: pile-w/h ( pile gadget offset -- )
-    rot dup pile-gap y [ + ] change
-    pile-fill * >fixnum over pref-size dup y [ + ] change
-    >r + r> rot resize-gadget ;
-: vertically ( pile gadget -- ) 2dup w- 3dup pile-x/y pile-w/h ;
-
-M: pile layout* ( pile -- )
-    [
-        dup gadget-children [ vertically ] each-with
-    ] with-layout ;
-
-! A shelf is a box that lays out its contents horizontally.
-TUPLE: shelf gap align fill ;
-
-C: shelf ( align gap fill -- shelf )
-    <empty-gadget> over set-delegate
-    [ set-shelf-fill ] keep
-    [ set-shelf-gap ] keep
-    [ set-shelf-align ] keep ;
-
-: <default-shelf> 1/2 default-gap 0 <shelf> ;
-: <line-shelf> 0 0 1 <shelf> ;
-
-M: shelf pref-size ( pile -- w h )
-    [
-        dup shelf-gap swap gadget-children
-        [ length 1 - 0 max * width set ] keep
-        [
-            pref-size
-            height [ max ] change
-            width [ + ] change
-        ] each
-    ] with-pref-size ;
-
-: h- swap shape-h swap pref-size nip - ;
-: shelf-x/y rot shelf-align * >fixnum >r x get r> rot move-gadget ;
-: shelf-w/h ( pile gadget offset -- )
-    rot dup shelf-gap x [ + ] change
-    shelf-fill * >fixnum >r dup pref-size over x [ + ] change
-    r> drop rot resize-gadget ; 
-: horizontally ( pile gadget -- )
-    2dup h- 3dup shelf-x/y shelf-w/h ;
-
-M: shelf layout* ( pile -- )
-    [
-        dup gadget-children [ horizontally ] each-with
-    ] with-layout ;
-
-! A border lays out its children on top of each other, all with
-! a 5-pixel padding.
-TUPLE: border size ;
-
-C: border ( child delegate size -- border )
-    [ set-border-size ] keep
-    [ set-delegate ] keep
-    [ over [ add-gadget ] [ 2drop ] ifte ] keep ;
-
-: empty-border ( child -- border )
-    <empty-gadget> 5 <border> ;
-
-: line-border ( child -- border )
-    0 0 0 0 <etched-rect> <gadget> 5 <border> ;
-
-: filled-border ( child -- border )
-    0 0 0 0 <plain-rect> <gadget> 5 <border> ;
-
-: gadget-child gadget-children car ;
-
-: layout-border-x/y ( border -- )
-    dup border-size dup rot gadget-child move-gadget ;
-
-: layout-border-w/h ( border -- )
-    [ border-size 2 * ] keep
-    [ shape-w over - ] keep
-    [ shape-h rot - ] keep
-    gadget-child resize-gadget ;
-
-M: border pref-size ( border -- w h )
-    [ border-size 2 * ] keep
-    gadget-child pref-size >r over + r> rot + ;
-
-M: border layout* ( border -- )
-    dup layout-border-x/y layout-border-w/h ;
-
-! A stack just lays out all its children on top of each other.
-TUPLE: stack ;
-C: stack ( list -- stack )
-    <empty-gadget> over set-delegate
-    swap [ over add-gadget ] each ;
-
-: max-size ( stack -- w h )
-    [
-        [
-            dup
-            shape-w width [ max ] change
-            shape-h height [ max ] change
-        ] each
-    ] with-pref-size ;
-
-M: stack pref-size gadget-children max-size ;
-
-M: stack layout* ( stack -- )
-    dup gadget-children [
-        >r dup shape-w over shape-h r> resize-gadget
-    ] each drop ;
diff --git a/library/ui/piles.factor b/library/ui/piles.factor
new file mode 100644
index 0000000000..eb949c423a
--- /dev/null
+++ b/library/ui/piles.factor
@@ -0,0 +1,45 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
+IN: gadgets
+USING: errors generic hashtables kernel lists math namespaces
+sdl ;
+
+! A pile is a box that lays out its contents vertically.
+TUPLE: pile align gap fill ;
+
+C: pile ( align gap fill -- pile )
+    #! align: 0 left aligns, 1/2 center, 1 right.
+    #! gap: between each child.
+    #! fill: 0 leaves default width, 1 fills to pile width.
+    [ <empty-gadget> swap set-delegate ] keep
+    [ set-pile-fill ] keep
+    [ set-pile-gap ] keep
+    [ set-pile-align ] keep ;
+
+: <default-pile> 1/2 default-gap 0 <pile> ;
+: <line-pile> 0 0 1 <pile> ;
+
+M: pile pref-size ( pile -- w h )
+    [
+        dup pile-gap swap gadget-children
+        [ length 1 - 0 max * height set ] keep
+        [
+            pref-size
+            height [ + ] change
+            width [ max ] change
+        ] each
+    ] with-pref-size ;
+
+: w- swap shape-w swap pref-size drop - ;
+: pile-x/y ( pile gadget offset -- )
+    rot pile-align * >fixnum y get rot move-gadget ;
+: pile-w/h ( pile gadget offset -- )
+    rot dup pile-gap y [ + ] change
+    pile-fill * >fixnum over pref-size dup y [ + ] change
+    >r + r> rot resize-gadget ;
+: vertically ( pile gadget -- ) 2dup w- 3dup pile-x/y pile-w/h ;
+
+M: pile layout* ( pile -- )
+    [
+        dup gadget-children [ vertically ] each-with
+    ] with-layout ;
diff --git a/library/ui/scrolling.factor b/library/ui/scrolling.factor
index ae84e5f235..75a42edf15 100644
--- a/library/ui/scrolling.factor
+++ b/library/ui/scrolling.factor
@@ -1,3 +1,5 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
 IN: gadgets
 USING: generic kernel lists math namespaces threads ;
 
@@ -19,20 +21,13 @@ TUPLE: viewport x y ;
     [ set-viewport-y ] keep
     relayout ;
 
-: scroll>bottom ( viewport -- )
-    1 swap scroll-viewport ;
-
-: viewport-actions ( viewport -- )
-    [
-        [[ [ scroll>bottom ] [ scroll>bottom ] ]]
-    ] swap add-actions ;
+: scroll>bottom ( viewport -- ) 1 swap scroll-viewport ;
 
 C: viewport ( content -- viewport )
     [ <empty-gadget> swap set-delegate ] keep
     [ add-gadget ] keep
     0 over set-viewport-x
-    0 over set-viewport-y
-    dup viewport-actions ;
+    0 over set-viewport-y ;
 
 M: viewport pref-size gadget-child pref-size ;
 
@@ -43,9 +38,6 @@ M: viewport layout* ( viewport -- )
         ] keep prefer
     ] each-with ;
 
-: scroll>bottom ( viewport -- )
-    dup viewport-h swap scroll-viewport ;
-
 ! A slider scrolls a viewport.
 
 ! The offset slot is the y co-ordinate of the mouse relative to
@@ -119,8 +111,17 @@ TUPLE: scroller viewport slider ;
 : add-viewport 2dup set-scroller-viewport add-gadget ;
 : add-slider 2dup set-scroller-slider add-gadget ;
 
+: viewport>bottom 1 swap scroll-viewport ;
+: scroll>bottom ( scroller -- )
+    dup scroller-slider relayout
+    scroller-viewport viewport>bottom ;
+
+: scroller-actions ( scroller -- )
+    [ scroll>bottom ] [ scroll>bottom ] set-action ;
+
 C: scroller ( gadget -- scroller )
     #! Wrap a scrolling pane around the gadget.
     [ <line-shelf> swap set-delegate ] keep
     [ >r <viewport> r> add-viewport ] keep
-    [ dup scroller-viewport <slider> swap add-slider ] keep ;
+    [ dup scroller-viewport <slider> swap add-slider ] keep
+    dup scroller-actions ;
diff --git a/library/ui/shelves.factor b/library/ui/shelves.factor
new file mode 100644
index 0000000000..b2b0467a40
--- /dev/null
+++ b/library/ui/shelves.factor
@@ -0,0 +1,42 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
+IN: gadgets
+USING: errors generic hashtables kernel lists math namespaces
+sdl ;
+
+! A shelf is a box that lays out its contents horizontally.
+TUPLE: shelf gap align fill ;
+
+C: shelf ( align gap fill -- shelf )
+    <empty-gadget> over set-delegate
+    [ set-shelf-fill ] keep
+    [ set-shelf-gap ] keep
+    [ set-shelf-align ] keep ;
+
+: <default-shelf> 1/2 default-gap 0 <shelf> ;
+: <line-shelf> 0 0 1 <shelf> ;
+
+M: shelf pref-size ( pile -- w h )
+    [
+        dup shelf-gap swap gadget-children
+        [ length 1 - 0 max * width set ] keep
+        [
+            pref-size
+            height [ max ] change
+            width [ + ] change
+        ] each
+    ] with-pref-size ;
+
+: h- swap shape-h swap pref-size nip - ;
+: shelf-x/y rot shelf-align * >fixnum >r x get r> rot move-gadget ;
+: shelf-w/h ( shelf gadget offset -- )
+    rot dup shelf-gap x [ + ] change
+    shelf-fill * >fixnum >r dup pref-size over x [ + ] change
+    r> + rot resize-gadget ; 
+: horizontally ( shelf gadget -- )
+    2dup h- 3dup shelf-x/y shelf-w/h ;
+
+M: shelf layout* ( pile -- )
+    [
+        dup gadget-children [ horizontally ] each-with
+    ] with-layout ;
diff --git a/library/ui/stacks.factor b/library/ui/stacks.factor
new file mode 100644
index 0000000000..d3f7bcf107
--- /dev/null
+++ b/library/ui/stacks.factor
@@ -0,0 +1,27 @@
+! Copyright (C) 2005 Slava Pestov.
+! See http://factor.sf.net/license.txt for BSD license.
+IN: gadgets
+USING: errors generic hashtables kernel lists math namespaces
+sdl ;
+
+! A stack just lays out all its children on top of each other.
+TUPLE: stack ;
+C: stack ( list -- stack )
+    <empty-gadget> over set-delegate
+    swap [ over add-gadget ] each ;
+
+: max-size ( stack -- w h )
+    [
+        [
+            dup
+            shape-w width [ max ] change
+            shape-h height [ max ] change
+        ] each
+    ] with-pref-size ;
+
+M: stack pref-size gadget-children max-size ;
+
+M: stack layout* ( stack -- )
+    dup gadget-children [
+        >r dup shape-w over shape-h r> resize-gadget
+    ] each drop ;