SWI-Prolog 7.4.2 Reference Manual: Section 1.4

## 1.4 Support the SWI-Prolog project

You can support the SWI-Prolog project in several ways. Academics are invited to cite one of the publications2http://www.swi-prolog.org/Publications.html on SWI-Prolog. Users can help by identifying and/or fixing problems with the code or its documentation.3http://www.swi-prolog.org/howto/SubmitPatch.html. Users can contribute new features or, more lightweight, contribute packs4http://www.swi-prolog.org/pack/list. Commercial users may consider contacting the developers5mailto:info@swi-prolog.org to sponsor the development of new features or seek for opportunities to cooperate with the developers or other commercial users.