Some small parts of the Prolog code of SWI-Prolog are modified versions of the corresponding Edinburgh C-Prolog code: grammar rule compilation and writef/2. Also some of the C-code originates from C-Prolog: finding the path of the currently running executable and some of the code underlying absolute_file_name/2. Ideas on programming style and techniques originate from C-Prolog and Richard O'Keefe's thief editor. An important source of inspiration are the programming techniques introduced by Anjo Anjewierden in PCE version 1 and 2.
I also would like to thank those who had the fade of using the early versions of this system, suggested extensions or reported bugs. Among them are Anjo Anjewierden, Huub Knops, Bob Wielinga, Wouter Jansweijer, Luc Peerdeman, Eric Nombden, Frank van Harmelen, Bert Rengel.
Martin Jansche (email@example.com) has been so kind to reorganise the sources for version 2.1.3 of this manual.
Horst von Brand has been so kind to fix many typos in the 2.7.14 manual. Thanks!
Bart Demoen and Tom Schrijvers have helped me adding coroutining, constraints, global variables and support for cyclic terms to the kernel. Tom has provided the integer interval constraint solver, the CHR compiler and some of the coroutining predicates.
Paul Singleton has integrated Fred Dushin's Java-calls-Prolog side with his Prolog-calls-Java side into the current bidirectional JPL interface package.
Richard O'Keefe is gratefully acknowledged for his efforts to educate beginners as well as valuable comments on proposed new developments.
Scientific Software and Systems Limited, www.sss.co.nz has sponsored the development if the SSL library as well as unbounded integer and rational number arithmetic.
Leslie de Koninck has made clp(QR) available to SWI-Prolog.
Markus Triska has contributed to various libraries.
Paulo Moura's great experience in maintaining Logtalk for many Prolog systems including SWI-Prolog has helped in many places fixing compatibility issues. He also worked on the MacOS port and fixed many typos in the 5.6.9 release of the documentation.