Extension Language Kit
Elk
(Elk) A Scheme interpreter by Oliver Laumann <net@cs.tu-berlin.de> and Carsten Bormann <cabo@cs.tu-berlin.de> of the Technical University of Berlin. Elk was designed to be used as a general extension language. New types and primitive procedures can easily be added. It has first-class environments, dynamic-wind, fluid-let, macros, autoloading and a dump. It provides interfaces to Xlib, Xt and various widget sets; dynamic loading of extensions and object files; almost all artificial limitations removed; generational/incremental garbage collector; Unix system call extensions; Records (structures) and bit strings.
Version: 2.2 is mostly R3RS compatible and runs on Unix, Ultrix, VAX, Sun-3, Sun-4, 68000, i386, MIPS, IBM PC RT, RS/6000, HP700, SGI, Sony, MS-DOS (gcc+DJGPP or go32).