30 Years

Welcome to LPA

LPA provides a range of software development tools for both programmers and non-programmers who wish to deliver knowledge-based decision support and expert systems.

BDS-PROLOG 8.1 is Here!

To coincide with the 34th anniversary of its birth, a new version of BDS-PROLOG, 8.1, has been released. This builds on the supreme reliability of version 8.0, with a number of new internal optimisations and a good handful of additional example and library programs, including a near-foolproof WORDLE solver! Available in both 32-bit and 64-bit versions for Windows, and 32-bit for MS-DOS, please find out more on the product links in the above menu.

Paris: 50 Years of Prolog

Almost exactly one year ago, on 10th November 2022, the Association of Logic Programming (ALP) hosted a special one-day symposium in Paris, to celebrate the 50th anniversary of Prolog. Both Brian D Steel and Clive Spenser attended this well-supported event, a wonderful chance to meet up with some of our customers and colleagues, and also to mingle with over 200 other Prolog users, researchers and implementers, many of whom had travelled long distances to get to the event.

2023 - 34 Years of BDS-PROLOG

Brian wrote the first lines of assembler code for "386-PROLOG", a true 32-bit Prolog engine, on 2nd November 1989. Using a DOS extender, the first version of 386-PROLOG ran on MS-DOS, smashing the 640kb barrier and giving access to up to 4 gigabytes of memory. He started work on a second version almost exactly a year later, this time targeting Windows 3.0, using his own 32-bit extender technology. 386-PROLOG was renamed DOS-PROLOG, and WIN-PROLOG was born.

Both these systems are still actively maintained and developed, and in the summer of 2018, Brian completed a true 64-bit version of WIN-PROLOG, giving Prolog effectively unlimited memory. The current release both of the 32-bit and 64-bit systems, is version 8.1, built on 2nd November 2023, the exact 34th anniversary!


Introducing Weblog!

Weblog is the fresh, new toolkit which provides a direct, streamlined way of combining beautifully designed web pages with logical scripts written in Prolog.

Weblog separates the processes of website design and content programming, so that web pages can be created in familiar tools such as DreamWeaver, PhotoShop and Illustrator, independently of the application code which supports them.