diff --git a/ueforth/Makefile b/ueforth/Makefile
index c990d60..168a746 100644
--- a/ueforth/Makefile
+++ b/ueforth/Makefile
@@ -11,8 +11,13 @@ all: $(TARGETS)
 out/gen:
 	mkdir -p out/gen
 
-out/gen/boot.h: common/source_to_string.js common/boot.fs | out/gen
-	$^ boot >$@
+POSIX_BOOT = common/boot.fs posix/posix.fs
+out/gen/posix_boot.h: common/source_to_string.js $(POSIX_BOOT) | out/gen
+	echo "ok" | cat $(POSIX_BOOT) - | $< boot >$@
+
+ARDUINO_BOOT = common/boot.fs posix/posix.fs
+out/gen/arduino_boot.h: common/source_to_string.js $(ARDUINO_BOOT) | out/gen
+	echo "ok" | cat $(ARDUINO_BOOT) - | $< boot >$@
 
 out/gen/dump_web_opcodes: web/dump_web_opcodes.c common/opcodes.h | out/gen
 	$(CC) $(CFLAGS) $< -o $@
@@ -32,7 +37,7 @@ out/web/terminal.html: web/terminal.html | out/web
 out/web/ueforth.js: \
         web/fuse_web.js \
         web/web.template.js \
-        out/gen/boot.h \
+        common/boot.fs \
         out/gen/web_dict.js \
         out/gen/web_cases.js | out/web
 	$^ >$@
@@ -44,7 +49,7 @@ out/posix/ueforth: \
     posix/posix_main.c \
     common/opcodes.h \
     common/core.h \
-    out/gen/boot.h | out/posix
+    out/gen/posix_boot.h | out/posix
 	$(CC) $(CFLAGS) $< -o $@ $(LIBS)
 
 out/arduino:
@@ -55,7 +60,7 @@ out/arduino/ueforth.ino: \
         arduino/arduino.template.ino \
         common/opcodes.h \
         common/core.h \
-        out/gen/boot.h | out/arduino
+        out/gen/arduino_boot.h | out/arduino
 	$^ >$@
 
 clean:
diff --git a/ueforth/common/boot.fs b/ueforth/common/boot.fs
index b98f293..6a4d0c6 100644
--- a/ueforth/common/boot.fs
+++ b/ueforth/common/boot.fs
@@ -19,13 +19,10 @@
 : > ( a b -- a>b ) swap - 0< ;
 : = ( a b -- a!=b ) - 0= ;
 : <> ( a b -- a!=b ) = 0= ;
-: emit ( n -- ) >r rp@ 1 type rdrop ;
-: bl 32 ;   : space bl emit ;
-: nl 10 ;   : cr nl emit ;
+: bl 32 ;   : nl 10 ;
 : 1+ 1 + ;   : 1- 1 - ;
 : 2* 2 * ;   : 2/ 2 / ;
 : +! ( n a -- ) swap over @ + swap ! ;
-: bye   0 sysexit ;
 
 ( Cells )
 : cell+ ( n -- n ) cell + ;
@@ -78,8 +75,14 @@
 : max 2dup < if nip else drop then ;
 : abs ( n -- +n ) dup 0< if negate then ;
 
-( Postpone - done here so we have ['] and IF )
+( Dictionary Format )
+: >name ( xt -- a n ) 3 cells - dup @ swap over aligned - swap ;
+: >link ( xt -- a ) 2 cells - @ ;
 : >flags ( xt -- flags ) cell - ;
+: >body ( xt -- a ) 2 cells + ;
+: >:body ( xt -- a ) cell+ ;
+
+( Postpone - done here so we have ['] and IF )
 : immediate? ( xt -- f ) >flags @ 1 and 0= 0= ;
 : postpone ' dup immediate? if , else aliteral ['] , , then ; immediate
 
@@ -111,6 +114,22 @@ variable handler
 : throw   handler @ rp! r> handler ! r> swap >r sp! drop r> ;
 ' throw 'throw !
 
+( Deferred Words )
+: defer   create 0 , does> @ execute ;
+: is    ' >body ! ;
+
+( Values )
+: value ( n -- ) create , does> @ ;
+: to ( n -- ) state @ if postpone ['] postpone >body postpone !
+                      else ' >body ! then ; immediate
+
+( Defer I/O to platform specific )
+defer type
+defer key
+defer bye
+: emit ( n -- ) >r rp@ 1 type rdrop ;
+: space bl emit ;   : cr nl emit ;
+
 ( Numeric Output )
 variable hld
 : pad ( -- a ) here 80 + ;
@@ -125,8 +144,8 @@ variable hld
 : str ( n -- b u ) dup >r abs <# #s r> sign #> ;
 : hex ( -- ) 16 base ! ;
 : decimal ( -- ) 10 base ! ;
-: u. ( u -- ) <# #s #> space type ;
-: . ( w -- ) base @ 10 xor if u. exit then str space type ;
+: u. ( u -- ) <# #s #> type space ;
+: . ( w -- ) base @ 10 xor if u. exit then str type space ;
 : ? ( a -- ) @ . ;
 
 ( Strings )
@@ -139,14 +158,11 @@ variable hld
 : z"   postpone s" state @ if postpone drop else drop then ; immediate
 
 ( Examine Dictionary )
-: >name ( xt -- a n ) 3 cells - dup @ swap over aligned - swap ;
-: >link ( xt -- a ) 2 cells - @ ;
-: >body ( xt -- a ) cell+ ;
 : see. ( xt -- ) >name type space ;
 : see-one ( xt -- xt+1 )
    dup @ dup ['] DOLIT = if drop cell+ dup @ . else see. then cell+ ;
 : exit= ( xt -- ) ['] exit = ;
-: see-loop   >body begin see-one dup @ exit= until ;
+: see-loop   >:body begin see-one dup @ exit= until ;
 : see   cr ['] : see.  ' dup see.  see-loop drop  ['] ; see.  cr ;
 : words   last @ begin dup see. >link dup 0= until drop cr ;
 
@@ -165,4 +181,4 @@ create input-buffer   input-limit allot
 : eval-line   begin >in @ #tib @ < while eval1 repeat ;
 : query   begin ['] eval-line catch if ." ERROR" cr then prompt refill drop again ;
 : ok   ." uEForth" cr prompt refill drop query ;
-ok
+
diff --git a/ueforth/common/core.h b/ueforth/common/core.h
index 446b728..4303a2a 100644
--- a/ueforth/common/core.h
+++ b/ueforth/common/core.h
@@ -88,6 +88,7 @@ static cell_t *eval1(cell_t *sp, cell_t *call) {
         *++sp = n;
       }
     } else {
+      //fwrite((void *) name, 1, len, stderr);
       *++sp = -1;
       *call = g_sys.tthrow;
     }
diff --git a/ueforth/common/source_to_string.js b/ueforth/common/source_to_string.js
index 27db95a..d5c6bb1 100755
--- a/ueforth/common/source_to_string.js
+++ b/ueforth/common/source_to_string.js
@@ -2,8 +2,8 @@
 
 var fs = require('fs');
 
-var source = fs.readFileSync(process.argv[2]).toString();
-var name = process.argv[3];
+var source = fs.readFileSync(process.stdin.fd).toString();
+var name = process.argv[2];
 
 source = source.replace(/["]/g, '\\"');
 source = '" ' + source.split('\n').join(' "\n" ') + ' "';
diff --git a/ueforth/posix/posix.fs b/ueforth/posix/posix.fs
new file mode 100644
index 0000000..2f08dfa
--- /dev/null
+++ b/ueforth/posix/posix.fs
@@ -0,0 +1,33 @@
+( Shared Library Handling )
+1 constant RTLD_LAZY
+2 constant RTLD_NOW
+: dlopen ( n z -- a ) [ 0 z" dlopen" dlsym aliteral ] call2 ;
+create calls
+' call0 , ' call1 , ' call2 , ' call3 , ' call4 ,
+' call5 , ' call6 , ' call7 , ' call8 , ' call9 ,
+: sofunc ( z n a -- ) swap >r swap dlsym create , r> cells calls + @ ,
+                      does> dup @ swap cell+ @ execute ;
+: sysfunc ( z n -- ) 0 sofunc ;
+: shared-library ( z -- ) RTLD_NOW dlopen create ,
+               ( z n -- ) does> @ sofunc ;
+
+( Major Syscalls )
+z" close" 1 sysfunc close
+z" read" 3 sysfunc read
+z" write" 3 sysfunc write
+z" open" 3 sysfunc open
+z" creat" 2 sysfunc creat
+z" exit" 1 sysfunc sysexit
+
+( Default Pipes )
+0 constant stdin
+1 constant stdout
+2 constant stderr
+
+( Hookup I/O )
+: stdout-write ( a n -- ) stdout -rot write drop ;
+' stdout-write is type
+: stdin-key ( -- n ) 0 >r stdin rp@ 1 read drop r> ;
+' stdin-key is key
+: posix-bye   0 sysexit ;
+' posix-bye is bye
diff --git a/ueforth/posix/posix_main.c b/ueforth/posix/posix_main.c
index 73808ba..d52d395 100644
--- a/ueforth/posix/posix_main.c
+++ b/ueforth/posix/posix_main.c
@@ -18,13 +18,10 @@
   X("CALL7", OP_CALL7, tos = ((cell_t (*)()) tos)(sp[-6], sp[-5], sp[-4], sp[-3], sp[-2], sp[-1], *sp); sp -= 7) \
   X("CALL8", OP_CALL8, tos = ((cell_t (*)()) tos)(sp[-7], sp[-6], sp[-5], sp[-4], sp[-3], sp[-2], sp[-1], *sp); sp -= 8) \
   X("CALL9", OP_CALL9, tos = ((cell_t (*)()) tos)(sp[-8], sp[-7], sp[-6], sp[-5], sp[-4], sp[-3], sp[-2], sp[-1], *sp); sp -= 9) \
-  X("TYPE", OP_TYPE, fwrite((void *) *sp, 1, tos, stdout); --sp; DROP) \
-  X("KEY", OP_KEY, DUP; tos = fgetc(stdin)) \
-  X("SYSEXIT", OP_SYSEXIT, DUP; exit(tos)) \
 
 #include "common/core.h"
 
-#include "gen/boot.h"
+#include "gen/posix_boot.h"
 
 int main(int argc, char *argv[]) {
   ueforth(boot, sizeof(boot));