The XLISP family

XLISP is a family of multi-platform LISP implementations, they comprise of a Scheme compatible bytecode compiler called Xlisp originally written by David Betz and he added few object oriented features to the basic Scheme language. The core runtime is written in C while the rest is implemented in XLISP itself and the program was released in to the public domain up until about version 2.1 where the license was changed. Xlisp 2.1 is also the last Xlisp version to be available in an OS/2 port, although that post is called XLISP-PLUS on Hobbes.

XLISP-PLUS

Tom Almy had ported Xlisp to OS/2 and DOS and added a Microsoft Windows version, with Xlisp 2.1 he forked the program and introduced his own version called XLISP-PLUS. It is not known if the fork was due to the licence change introduced with version 2.1 or if it is due to Almy's interest in getting more Common Lisp features working on the Xlisp system, but the original author resisted adding anything but an object system to the base Scheme specification.

XLISP-PLUS adds a host of Common Lisp features to Xlisp

After 16 years of inactivity, Mr Almy suddenly kicked into life in early 2016 and created a new 3.05 version of XLISP-PLUS however the libraries will function with the 3.04 OS/2 version, and he has also created a new Windows version that will work under OS/2.

XLISP-STAT

A fork of Xlisp 2.1 with statistical additions

. Winterp is a derivative of XLISP-PLUS.

Version

• XLisp-Plus v3.04 (1999/01/09)
• XLisp v2.1 (1995/12/27)
• Xlisp v3 (1997 - some trivial bug fixes in 1998 and 2002)

Only released in a version for Microsoft Windows

Links

• XLisp-Plus v2.1 (1995/12/27)
• XLISP-Plus Homepage
• XLISP Homepage

Licence and availability

• Open source software
• Xlisp version 2.1 and later are released under the Four Clause BSD Licence, versions prior to that are in the public domain.

Author

• David Betz - Original Xlisp author
• Tom Almy Original porter of Xlisp to OS/2, maintainer of XLISP-PLUS