We have access to the 2007 engine which is windows based only. The engine cannot work on other systems with out using an emulation tool due to using windows only system calls. Specifically the use of the windows API and Directx
. You can search google for more information on platform only code, here is a start.
The 2009 sdk can be used on a mac with OpenGL but we are not using that sdk. Lack of custom shader support and few other reasons.