diff --git a/ueforth/Makefile b/ueforth/Makefile
index 59fa02d..7349bff 100644
--- a/ueforth/Makefile
+++ b/ueforth/Makefile
@@ -115,25 +115,23 @@ $(GEN):
 
 POSIX_BOOT =  common/boot.fs common/vocabulary.fs common/hide_calls.fs common/ansi.fs \
               posix/posix.fs posix/posix_highlevel.fs \
-              common/highlevel.fs common/filetools.fs posix/posix_desktop.fs \
-              common/tasks.fs common/streams.fs common/blocks.fs posix/args.fs \
-              common/utils.fs
+              common/utils.fs common/highlevel.fs common/filetools.fs posix/posix_desktop.fs \
+              common/tasks.fs common/streams.fs common/blocks.fs posix/args.fs
 $(GEN)/posix_boot.h: common/source_to_string.js $(POSIX_BOOT) | $(GEN)
 	echo "ok" | cat $(POSIX_BOOT) - | $< boot >$@
 
 WINDOWS_BOOT = common/boot.fs common/vocabulary.fs common/hide_calls.fs common/ansi.fs \
                windows/windows.fs windows/windows_highlevel.fs common/highlevel.fs \
-               common/tasks.fs common/streams.fs common/blocks.fs \
-               common/utils.fs
+               common/utils.fs common/tasks.fs common/streams.fs common/blocks.fs
 $(GEN)/windows_boot.h: common/source_to_string.js $(WINDOWS_BOOT) | $(GEN)
 	echo "ok" | cat $(WINDOWS_BOOT) - | $< boot >$@
 
 ARDUINO_BOOT = common/boot.fs common/vocabulary.fs \
                arduino/arduino.fs arduino/arduino_highlevel.fs \
-               arduino/hide_io.fs \
-               common/highlevel.fs common/filetools.fs \
+               arduino/hide_io.fs common/highlevel.fs \
+               common/filetools.fs common/utils.fs \
                common/tasks.fs common/streams.fs arduino/arduino_server.fs \
-               arduino/esp_camera.fs common/blocks.fs common/utils.fs \
+               arduino/esp_camera.fs common/blocks.fs \
                arduino/autoboot.fs
 $(GEN)/arduino_boot.h: common/source_to_string.js $(ARDUINO_BOOT) | $(GEN)
 	echo "ok" | cat $(ARDUINO_BOOT) - | $< boot >$@
diff --git a/ueforth/common/testing.fs b/ueforth/common/testing.fs
index 1d7abd9..47087b6 100644
--- a/ueforth/common/testing.fs
+++ b/ueforth/common/testing.fs
@@ -1,9 +1,4 @@
-( Utilities, probably should go elsewhere )
-: mem= ( a a n -- f)
-   for aft 2dup c@ swap c@ <> if 2drop rdrop 0 exit then 1+ swap 1+ then next 2drop -1 ;
-: str= ( a n a n -- f) >r swap r@ <> if rdrop 2drop 0 exit then r> mem= ;
-: startswith? ( a n a n -- f ) >r swap r@ < if rdrop 2drop 0 exit then r> mem= ;
-: assert ( f -- ) 0= throw ;
+also ansi also posix
 
 ( Support for eval tests )
 1000 constant expect-limit
@@ -45,9 +40,7 @@ variable tests-found   variable tests-run    variable tests-passed
 : check-fresh   depth if }confirm ."  DEPTH LEAK! " depth . 1 throw then ;
 : wrap-test ( xt -- ) expect-reset >r check-fresh r> execute check-fresh expect-finish ;
 : red   1 fg ;   : green   2 fg ;   : hr   40 for [char] - emit next cr ;
-ansi
 : replace-line   13 emit clear-to-eol ;
-forth
 : label-test ( xt -- ) replace-line >name type ;
 : run-test ( xt -- ) dup label-test confirm{ ['] wrap-test catch }confirm
    if drop ( cause xt restored on throw ) red ."  FAILED" normal cr
@@ -62,9 +55,8 @@ forth
    else
      ."   FAILED: " red tests-run @ tests-passed @ - . normal cr
    then hr ;
-posix
 : run-tests
    reset-test-counters ['] count-test for-tests
    ['] run-test for-tests show-test-results
    tests-passed @ tests-found @ <> sysexit ;
-forth
+only forth
diff --git a/ueforth/common/utils.fs b/ueforth/common/utils.fs
index 9bb1fdc..7736849 100644
--- a/ueforth/common/utils.fs
+++ b/ueforth/common/utils.fs
@@ -2,4 +2,13 @@
 
 : .s   ." <" depth <# #s #> type ." > "
        depth 0 max for aft sp@ r@ cells - @ . then next cr ;
+: assert ( f -- ) 0= throw ;
+
+internals definitions
+: mem= ( a a n -- f)
+   for aft 2dup c@ swap c@ <> if 2drop rdrop 0 exit then 1+ swap 1+ then next 2drop -1 ;
+forth definitions also internals
+: str= ( a n a n -- f) >r swap r@ <> if rdrop 2drop 0 exit then r> mem= ;
+: startswith? ( a n a n -- f ) >r swap r@ < if rdrop 2drop 0 exit then r> mem= ;
+only forth definitions
 
diff --git a/ueforth/common/vocabulary.fs b/ueforth/common/vocabulary.fs
index 7833a6d..2155280 100644
--- a/ueforth/common/vocabulary.fs
+++ b/ueforth/common/vocabulary.fs
@@ -13,12 +13,18 @@
 : }transfer ;
 : transfer{ begin ' dup ['] }transfer = if drop exit then transfer-xt again ;
 
+( Watered down versions of these )
+: only   forth 0 context cell+ ! ;
+: last-voc ( -- a) context begin dup @ while cell+ repeat ;
+: also   context context cell+ last-voc over - cell+ cmove> ;
+: sealed   0 current @ ! ;
+
 ( Hide some words in an internals vocabulary )
 vocabulary internals   internals definitions
 transfer{
-  transfer-xt
+  transfer-xt last-voc
   branch 0branch donext dolit
-  'notfound notfound
+  'context 'notfound notfound
   immediate? input-buffer ?echo ?echo-prompt
   evaluate1 evaluate-buffer
   'sys 'heap aliteral