CLISP includes an interpreter, a compiler, a debugger, CLOS, MOP, a foreign language interface, i18n, regular expressions, a socket interface, and more. An X11 interface is available through CLX, Garnet and CLUE/CLIO. Command line editing is provided by readline. CLISP runs Maxima, ACL2 and many other Common Lisp packages.

CLISP runs on most GNU and Unix systems (Linux, FreeBSD, NetBSD, OpenBSD, Solaris, Tru64, HP-UX, BeOS, NeXTstep, IRIX, AIX, Mac OS X and others) and on other systems (Windows NT/2000/XP/Vista, Windows 95/98/ME) and needs only 4 MB of RAM.

CLISP is Free Software and may be distributed under the terms of GNU GPL.