I saw that in the mandatory dependency list, CG for nvidia is needed. Does that mean that CS can only run nvidia graphics hardware?
What happens if I wish to port CS to an embedded platform that has its own GPU hardware?
Three things: In version 2.0 or older CG is not *really* required. It is just very recommended since a lot of shaders depend on it.
Additionaly the CG from nvidia is not restricted to nvidia hardware. It works for AMD, Intel Graphics, ...
Starting in CS 2.1 (not released yet) we also support GLSL so then the dependency on CG is even lower.
But in summary, you should not worry. There is no limitation to nvidia hardware at all. Look up the CG toolkit
on google. You can see that it is also for other hardware.