While commercial products are rarely open source, many different projects have explored the possibilities of opening up the code to the community -- and in this feature, Gamasutra looks at some examples and speaks to the minds behind them.]

The relationship between creator and audience in video games is more complicated than any other creative form. Developers can be artists, teachers, entertainers, scientists, or collaborators -- and often they must fill several of those roles simultaneously.

The role of the player is no less involved: actor, viewer, historian, student, lab rat, or leader -- all are roles he or she must be ready to play. Open source games capture this fullness of purpose, showing them at their most mechanical and most creative.

Giving players access to source code has been a part of gaming's history for years, from the earliest MUDs to Tim Sweeney's ZZT. As console gaming's proprietary hardware and its closely guarded development tools slowly squeezed PC play from its central place in the industry the idea of open source play declined.

Yet, everything connected to media and technology in the last ten years has taught us the future will be collaborative and the future is actually now. In recent years even console games have begun to realize there is profit in involving players in content creation, from Far Cry 2's extensive map editor to LittleBigPlanet 2's creation tools, which were so flexible that Media Molecule designed most of it's in-house levels with them.

And through it all, an active and growing number of PC games have kept the open source flame alive in a variety of ways.....