diff --git a/ueforth/common/boot.fs b/ueforth/common/boot.fs
index 240a91c..e73c1e6 100644
--- a/ueforth/common/boot.fs
+++ b/ueforth/common/boot.fs
@@ -52,25 +52,29 @@
 : 2@ ( a -- lo hi ) dup @ swap cell+ @ ;
 : 2! ( lo hi a -- ) dup >r cell+ ! r> ! ;
 
-( System Variables )
-: 'tib ( -- a ) 'sys 0 cells + ;
-: #tib ( -- a ) 'sys 1 cells + ;
-: >in ( -- a ) 'sys 2 cells + ;
-: state ( -- a ) 'sys 3 cells + ;
-: base ( -- a ) 'sys 4 cells + ;
-: 'heap ( -- a ) 'sys 5 cells + ;
-: current ( -- a ) 'sys 6 cells + ;
-: 'context ( -- a ) 'sys 7 cells + ;  : context 'context @ cell+ ;
-: 'notfound ( -- a ) 'sys 8 cells + ;
-
 ( Dictionary )
-: here ( -- a ) 'heap @ ;
-: allot ( n -- ) 'heap +! ;
+: here ( -- a ) 'sys @ ;
+: allot ( n -- ) 'sys +! ;
 : aligned ( a -- a ) cell 1 - dup >r + r> invert and ;
 : align   here aligned here - allot ;
 : , ( n --  ) here ! cell allot ;
 : c, ( ch -- ) here c! 1 allot ;
 
+( Constants and Variables )
+: constant ( n "name" -- ) create , does> @ ;
+: variable ( "name" -- ) create 0 , ;
+
+( System Variables )
+: sys: ( a -- a' "name" ) dup constant cell+ ;
+'sys   sys: 'heap         sys: current       sys: 'context       sys: 'notfound
+       sys: 'heap-start   sys: 'heap-size    sys: 'stack-cells
+       sys: 'boot         sys: 'boot-size
+       sys: 'tib          sys: #tib          sys: >in
+       sys: state         sys: base
+       sys: 'argc         sys: 'argv         sys: 'runner
+: context ( -- a ) 'context @ cell+ ;
+: remaining ( -- n ) 'heap-start @ 'heap-size @ + 'heap @ - ;
+
 ( Compilation State )
 : [ 0 state ! ; immediate
 : ] -1 state ! ; immediate
@@ -112,10 +116,6 @@
 : immediate? ( xt -- f ) >flags @ 1 and 0= 0= ;
 : postpone ' dup immediate? if , else aliteral ['] , , then ; immediate
 
-( Constants and Variables )
-: constant ( n "name" -- ) create , does> @ ;
-: variable ( "name" -- ) create 0 , ;
-
 ( Stack Convience )
 sp@ constant sp0
 rp@ constant rp0
@@ -256,3 +256,6 @@ create input-buffer   input-limit allot
 : quit    begin ['] evaluate-buffer catch
           if 0 state ! sp0 sp! fp0 fp! rp0 rp! ." ERROR" cr then
           prompt refill drop again ;
+: raw-ok   ."  v{{VERSION}} - rev {{REVISION}}" cr
+           remaining . ." bytes heap free" cr
+           prompt refill drop quit ;
diff --git a/ueforth/common/core.h b/ueforth/common/core.h
index bfe0c4d..81e9449 100644
--- a/ueforth/common/core.h
+++ b/ueforth/common/core.h
@@ -28,12 +28,18 @@
 #endif
 
 static struct {
+  cell_t *heap, **current, ***context, notfound;
+  cell_t *heap_start;
+  cell_t heap_size, stack_cells;
+  const char *boot;
+  cell_t boot_size;
   const char *tib;
   cell_t ntib, tin, state, base;
-  cell_t *heap, **current, ***context, notfound;
   int argc;
   char **argv;
   cell_t *(*runner)(cell_t *rp);  // pointer to forth_run
+
+  // Layout not used by Forth.
   cell_t *rp;  // spot to park main thread
   cell_t DOLIT_XT, DOFLIT_XT, DOEXIT_XT, YIELD_XT;
 } g_sys;
@@ -191,10 +197,16 @@ static cell_t *forth_run(cell_t *initrp);
 
 static void forth_init(int argc, char *argv[], void *heap,
                        const char *src, cell_t src_len) {
-  g_sys.heap = ((cell_t *) heap) + 4;  // Leave a little room.
-  float *fp = (float *) (g_sys.heap + 1); g_sys.heap += STACK_SIZE;
-  cell_t *rp = g_sys.heap + 1; g_sys.heap += STACK_SIZE;
-  cell_t *sp = g_sys.heap + 1; g_sys.heap += STACK_SIZE;
+  g_sys.heap_start = (cell_t *) heap;
+  g_sys.heap_size = HEAP_SIZE;
+  g_sys.stack_cells = STACK_CELLS;
+  g_sys.boot = src;
+  g_sys.boot_size = src_len;
+
+  g_sys.heap = g_sys.heap_start + 4;  // Leave a little room.
+  float *fp = (float *) (g_sys.heap + 1); g_sys.heap += STACK_CELLS;
+  cell_t *rp = g_sys.heap + 1; g_sys.heap += STACK_CELLS;
+  cell_t *sp = g_sys.heap + 1; g_sys.heap += STACK_CELLS;
 
   // FORTH vocabulary
   *g_sys.heap++ = 0; cell_t *forth = g_sys.heap;
diff --git a/ueforth/common/opcodes.h b/ueforth/common/opcodes.h
index bf215d7..cb5e5b5 100644
--- a/ueforth/common/opcodes.h
+++ b/ueforth/common/opcodes.h
@@ -103,5 +103,4 @@ typedef int64_t dcell_t;
                sp = evaluate1(sp, &tfp); \
                fp = tfp; w = *sp--; DROP; if (w) JMPW) \
   Y(EXIT, ip = (cell_t *) *rp--) \
-  X(";", SEMICOLON, UNSMUDGE(); COMMA(g_sys.DOEXIT_XT); g_sys.state = 0) \
-
+  X(";", SEMICOLON, UNSMUDGE(); COMMA(g_sys.DOEXIT_XT); g_sys.state = 0)
diff --git a/ueforth/common/vocabulary.fs b/ueforth/common/vocabulary.fs
index 67373c5..ec0c209 100644
--- a/ueforth/common/vocabulary.fs
+++ b/ueforth/common/vocabulary.fs
@@ -48,12 +48,14 @@ transfer{
   'context 'notfound notfound
   immediate? input-buffer ?echo ?arrow. arrow
   evaluate1 evaluate-buffer
-  'sys 'heap aliteral
+  'sys 'heap aliteral 'heap-start 'heap-size
+  'stack-cells 'boot 'boot-size
+  'argc 'argv 'runner
   leaving( )leaving leaving leaving,
   (do) (?do) (+loop)
   parse-quote digit $@ raw.s
   tib-setup input-limit
-  [SKIP] [SKIP]'
+  [SKIP] [SKIP]' raw-ok
 }transfer
 forth definitions
 
diff --git a/ueforth/esp32/platform.fs b/ueforth/esp32/platform.fs
index 047af44..0516217 100644
--- a/ueforth/esp32/platform.fs
+++ b/ueforth/esp32/platform.fs
@@ -63,4 +63,4 @@ led OUTPUT pinMode
 high led pin
 
 ( Setup entry )
-: ok   ." ESP32forth v{{VERSION}} - rev {{REVISION}}" cr prompt refill drop quit ;
+internals : ok   ." ESP32forth" raw-ok ; forth
diff --git a/ueforth/esp32/template.ino b/ueforth/esp32/template.ino
index 65818a8..bfbb185 100644
--- a/ueforth/esp32/template.ino
+++ b/ueforth/esp32/template.ino
@@ -85,7 +85,7 @@
 #include <sys/select.h>
 
 #define HEAP_SIZE (100 * 1024)
-#define STACK_SIZE 512
+#define STACK_CELLS 512
 #define INTERRUPT_STACK_CELLS 64
 
 // Optional hook to pull in words for userwords.h
diff --git a/ueforth/posix/posix.fs b/ueforth/posix/posix.fs
index 5f08721..8ed7049 100644
--- a/ueforth/posix/posix.fs
+++ b/ueforth/posix/posix.fs
@@ -189,4 +189,4 @@ O_RDWR constant r/w
 forth
 
 ( Setup entry )
-: ok   ." uEforth v{{VERSION}} - rev {{REVISION}}" cr prompt refill drop quit ;
+internals : ok   ." uEforth" raw-ok ; forth
diff --git a/ueforth/posix/posix_desktop.fs b/ueforth/posix/posix_desktop.fs
index 9b8ac6b..4f76cb6 100644
--- a/ueforth/posix/posix_desktop.fs
+++ b/ueforth/posix/posix_desktop.fs
@@ -13,9 +13,6 @@
 \ limitations under the License.
 
 ( Arguments )
-internals definitions
-: 'argc ( -- a ) 'sys 9 cells + ;
-: 'argv ( -- a ) 'sys 10 cells + ;
 forth definitions internals
 : argc ( -- n ) 'argc @ ;
 : argv ( n -- a n ) cells 'argv @ + @ z>s ;
diff --git a/ueforth/posix/posix_main.c b/ueforth/posix/posix_main.c
index acab5ec..1112356 100644
--- a/ueforth/posix/posix_main.c
+++ b/ueforth/posix/posix_main.c
@@ -21,7 +21,7 @@
 #include "common/calls.h"
 
 #define HEAP_SIZE (10 * 1024 * 1024)
-#define STACK_SIZE (64 * 1024)
+#define STACK_CELLS (8 * 1024)
 
 #define PLATFORM_OPCODE_LIST \
   Y(DLSYM, tos = (cell_t) dlsym(a1, a0); --sp) \
diff --git a/ueforth/posix/xlib_test.fs b/ueforth/posix/xlib_test.fs
index 86f6368..ab74229 100644
--- a/ueforth/posix/xlib_test.fs
+++ b/ueforth/posix/xlib_test.fs
@@ -47,7 +47,8 @@ create event xevent-size allot
   display gc white XSetBackground drop
   display window gc 0 0 width @ 2/ height @ 2/ XFillRectangle drop
 ;
-: de event xevent-size
+: handle-event
+  event xevent-size
   event c@ .
   event c@ Expose = if
     draw
@@ -67,5 +68,5 @@ create event xevent-size allot
   then
   event c@ MapNotify = if ." MapNotify" then
 cr ;
-: 1e display event XNextEvent drop de ;
-: gg begin draw 1e again ;
+: do-event display event XNextEvent drop handle-event ;
+: gg begin draw do-event again ;
diff --git a/ueforth/site/common.html b/ueforth/site/common.html
index d74bdc3..ad7c5d6 100644
--- a/ueforth/site/common.html
+++ b/ueforth/site/common.html
@@ -42,6 +42,7 @@ R| ( string| -- a n ) Creates a temporary counted string ending with |
 DUMP ( a n -- ) Dump a memory region
 SEE ( "name" -- ) Attempt to decompile a word
 VARIABLE ECHO -- Determines if commands are echoed
+REMAINING ( -- n ) Bytes remaining in Forth heap.
 </pre>
 
 <h5>Vocabularies</h5>
diff --git a/ueforth/web/web.template.js b/ueforth/web/web.template.js
index 6bd3c6b..129b728 100644
--- a/ueforth/web/web.template.js
+++ b/ueforth/web/web.template.js
@@ -17,7 +17,7 @@
 (function() {
 
 const HEAP_SIZE = (1024 * 1024);
-const STACK_SIZE = 4096;
+const STACK_CELLS = 4096;
 
 const boot = `
 {{boot}}
@@ -133,9 +133,9 @@ function Init() {
 
   InitDictionary();
   i32[g_sp>>2] = i32[g_heap>>2] + 1;
-  i32[g_heap>>2] += STACK_SIZE;
+  i32[g_heap>>2] += STACK_CELLS;
   i32[g_rp>>2] = i32[g_heap>>2] + 1;
-  i32[g_heap>>2] += STACK_SIZE;
+  i32[g_heap>>2] += STACK_CELLS;
   i32[((i32[g_current]>>2) - 4)>>2] = 1;  // Make ; IMMMEDIATE
   // Do not need DOLIT_XT, DOEXIT_XT, YIELD_XT (do by convention)
   i32[g_notfound>>2] = Find('DROP');
diff --git a/ueforth/windows/windows.fs b/ueforth/windows/windows.fs
index 4822525..0f3e987 100644
--- a/ueforth/windows/windows.fs
+++ b/ueforth/windows/windows.fs
@@ -160,5 +160,5 @@ r/o w/o or constant r/w
 forth
 
 ( Setup entry )
-: ok   ." uEforth v{{VERSION}} - rev {{REVISION}}" cr prompt refill drop quit ;
+internals : ok   ." uEforth" raw-ok ; forth
 ' forth ( leave on stack for fini.fs )
diff --git a/ueforth/windows/windows_main.c b/ueforth/windows/windows_main.c
index 27bfba1..3865672 100644
--- a/ueforth/windows/windows_main.c
+++ b/ueforth/windows/windows_main.c
@@ -33,7 +33,7 @@
 #include "common/calls.h"
 
 #define HEAP_SIZE (10 * 1024 * 1024)
-#define STACK_SIZE (64 * 1024)
+#define STACK_CELLS (8 * 1024)
 
 #define PLATFORM_OPCODE_LIST \
   Y(GETPROCADDRESS, \