STk
A Scheme interpreter blended with Ousterhout's Tk package by Erick Gallesio <eg@unice.fr>. STk expresses all of Tk as Scheme objects. STk includes a slow CLOS/Dylan-like object-oriented extension.
STk almost conforms to R4RS and runs on SunOS 4.1.x and Ultrix/MIPS.
ftp://kaolin.unice.fr/pub/STk-1.00.tar.gz. ftp://ftp.cs.indiana.edu/pub/scheme-repository/imp/STk-2.1.tar.Z.