I figure in the case of Outcast and Academy, since both games were Quake III engine based, very few specific modifications were made to support the features added by Raven to underlying engine code licensed from ID. Since ID had already open sourced QuakeIII many years ago, there were very few direct economic costs in terms of programming hours spent on the engine modification, so contributing those to the community would ensure free promotion and active use of the games for years to come. Keep in mind, open sourcing the engine does not include the game art (models, map, characters). Rebellion, on the other hand, is a pure in-house development. Now, while ownership may reside with the developer, Coolhand, it's certainly contractually subjective, and they maintain a copy for patching and maintenance purposes. They may, read most definitely, still need the approval of LEC (~Disney) to release any such code. In this case, some bean counter is only going to look at the programming hours involved and decide it's not in their interest to give anything away for free. I'm still waiting for Microsoft to make Windows 95 and Windows NT 4.0 open source too.