Prolog II+

A Prolog toolkit primarily developed by Alain Colmerauer who was the main inventor of the Prolog language in the early 70s. It features a number of additions to the language including constraint programming functions, the handling of infinite trees, extended program execution control structures (freeze) and support for PM programming. The toolkit came with a sophisticated development environment including a compiler, interpreter, an incremental garbage collector, a debugger and linker.

An unusual feature of the system is that it uses a Pascal based p-code and can generate Pascal output code if you want to integrate it into your Pascal project. In later versions the p-machine is replaced with a runtime written in C and gains a C interface.

The system was also available for a number of other operating systems, including a number of UNIX system, Microsoft Windows, the Apple Macintosh and DOS. The DOS version was considerably older and while it had all the same language features as those for other systems it lacked all the more advanced graphics programming and interaction features. There were also some custom versions delivered that targeted embedded systems and so on. Later versions of the system gained features such as Java bindings.

Version
Latest Windows, Mac and UNIX version: Prolog II+ v4.7 (2001)

Licence

 * Discontinued commercial software, the Windows, Mac and UNIX versions of Prolog II+ are now freeware.
 * Author: PrologIA

Links

 * Prolog Heritage - Has Prolog II/III/IV downloads, documentation and a bit of background.
 * A link to the MS Windows freeware release of the Prolog II+
 * PrologIA announcement (August 1993)
 * Mac and UNIX versions
 * Prolog II+ for Unix manual - In French
 * PRINCE - An old EU project that sought tho research how to modify and extend Prolog II+ to better integrate with financial services and industry.