The small (2K) RAM size is the limiting factor, not so much the code space. You'll find a few more options if you look beyond the atmega328 in the Arduino: 'av

The small (2K) RAM size is the limiting factor, not so much the code space. You'll find a few more options if you look beyond the atmega328 in the Arduino: 'avr lisp', 'avr scheme' The Lisps I've seen targeting AVRs have all used the atmega128 with 4KB of RAM and they still use external memory of some sort. Scrying (w/ 64KB external RAM): http://scrying.org/doku.php?id=scrying:interpreter_notes http://scrying.org/doku.php?id=scrying:interpreter_notes ActorNet (w/ 512KB external serial flash as virtual memory): http://osl.cs.uiuc.edu/nest/ActorNet-1.1.tar.gz http://osl.cs.uiuc.edu/nest/ActorNet-1.1.tar.gz http://osl.cs.uiuc.edu/docs/actornet/kwonActorNet.pdf http://osl.cs.uiuc.edu/docs/actornet/kwonActorNet.pdf Femto microlisp http://code.google.com/p/robobuilderlib/wiki/Femto http://code.google.com/p/robobuilderlib/wiki/Femto For my own REPL-fun on AVR microcontrollers, I've gone with amforth: http://amforth.sourceforge.net http://amforth.sourceforge.net