Berkeley Logo interpreter
This is a free (both senses) interpreter for the Logo programming language.
The current version is 6.0 if you're running wxWidgets, 5.4 if not. (They are made from the same source code.)
The distribution also includes version 5.3 for frozen platforms DOS and Mac Classic (pre-OS X).
I have become super busy doing other things (snap.berkeley.edu, bjc.edc.org) and so no development has happened on UCBLogo (a/k/a Berkeley Logo) in a decade or so. I would love for someone to take it over, and would even help you get started. (You'll need help because of the incredible chain of kludges herein.)
There is a 95% finished (but you know what that means) implementation of OOP in the style of Object Logo.
It would be especially great if the someone who takes it over knows how to make an interpreter run fast. /This/ interpreter is more or less the one from SICP 5.4 (the Explicit Control Evaluator) but with kludges added, mainly because not all Logo procedures return values.
There's one piece of good news: There's a Program Logic Manual in source/plm. So all the things I've forgotten aren't lost forever. :-)
Brian Harvey email@example.com