Orx
Orx - a portable open source game engine Orx is an open source, portable, lightweight, plugin-based, data-driven and extremely easy to use 2D-oriented game engine. It has been created to allow fast creation of games and prototypes. It's licensed under the zlib license. It's a very permissive (and short) license that allows one to use orx (and modify it at will) for free for any kind of projects, freeware or commercial, without any compensation. Orx provides a complete framework for game development and currently runs on windows (mingw and native using visual studio), linux (x86/x86_64), MacOS X (ppc/x86), iPhone/iPod Touch/iPad and Android. Orx is a full featured and powerful "2.5D" game engine. All objects and cameras are created in a 3D space, but only a 2D rendering plugin is currently available (however hooks are provided for those who need to roll out their own 3D rendering).
