All the recent issues with Digital Rights Management (DRM) have had various effects on the gaming industry. While on-line games and pay-per-play business models like World of Warcraft and recently Age of Conan are one popular way another recent addition is: give the games away for free! Some other MMOs allready use this model and instead charge for micro-transactions in-game to buy virtual items but now Electronic Arts and DICE are about to release a game in the popular Battlefield series for free, Battlefield: Heroes. The game is a simplified version of their original game, a more colourfull and “cartonish” look and to start the game you first have to log on to their website. If this is a new business model or a one time thing remains to be seen.
While we now have free operating systems and enterprise grade software (Open Office, Apache, MySQL, Firefox) we still do not have any “very popular” open source games. The only game programming I’ve tried myself was based on the open source C/C++ library called Allegro. Still no title coded in open source have made the gaming news to the best of my knowledge. Many open source games are “free copies” of exsisting games (Free Craft aka Star/Warcraft, FreeCiv aka Civilization etc), a list of examples can be found on the Wikipedia.