Bennu is a high level open source game development suite which focuses on modularity and portability, making it a perfect choice for cross-platform game development.
Although officialy it is only supported on Windows, Linux and GP2X Wiz (on the right), Bennu can run on multiple other platforms, including *BSD, MacOSX and other consoles such as the Wii, Dingoo A320, GP2X, or the classic Xbox.