XLISP-PLUS

Tom Almy had ported Xlisp to OS/2 and DOS and added a Microsoft Windows and Linux 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 but also adds a huge amount of bug fixes, however changes to the original Xlisp such as the bytecode compiler that was introduced with version 3 have not been integrated in this fork. The maintainer stopped updating XLISP-PLUS in 1999 when CLisp was taken over by the Free Software Foundation since the maintainer believed that with the frequent CLisp updates, Xlisp would become "unnecessary". However, after 16 years of inactivity, Mr. Almy suddenly kicked into life in early 2016 and created a new 3.05 version of XLISP-PLUS for MS Windows, Linux and MacOS X. While neither the DOS not the OS/2 version got an update the libraries will function with the 3.04 OS/2 version, and he has also created a new Windows 3.x 16-bit version that will work under OS/2.

Versions

• XLISP-PLUS v3.04 (1999-01-09)

Last known OS/2 version, note that the differences between 3.04 and 3.05 for other systems are primarily in the LISP portion of the code and if you download the xl305req.zip file from the XLISP-PLUS homepage you can run that version with the 3.04 version for OS/2.

• XLISP-PLUS v3.05 (2016-02-19)
• XLISP-PLUS v2.1gce (1998-05-28) - Last known Palm Pilot version

Licence

• XLISP-PLUS in mainly in the public domain, however a few of the included LISP library files have a no commercial usage clause.
• Tom Almy - Original porter of XLISP to OS/2, maintainer of XLISP-PLUS

Links

• XLISP-PLUS Home Page
• XLisp-Plus v2.1 (1995-12-27)
• XLisp-Plus for Macintosh