SWI-Prolog is a comprehensive implementation of the Prolog programming language. It provides robust multi-threading, supports many document formats and protocols as well as interfaces to other programming languages. It includes a powerful HTTP server framework. The online version (http://swish.swi-prolog.org) is completely written in Prolog and allows programming in your browser.
These details are provided for information only. No information here is legal advice and should not be used as such.