In this comp.lang.lisp post Ron Garret explains how he found and is in the process of exploring a copy of P-Lisp (PLisp) for the Apple IIe.
Addendum 06/24/08:
Ron explains how he created and released a disk image here.
Month: June 2008
Using PLT Scheme for Game Development
This presentation at the Vancouver Lisp Users Group sounds like a lot of fun.