DirectX or OpenGL for older computer
I've been doing C/C++ for about three and a half years now, and I'd like to get into some sort of graphics programming. I have Visual C++ 6.0, but my computer is rather old (350MHz PII, 128mb RAM).
The graphics I want to create are only 2D, so graphics performance is not much of a problem. I just want to ask which I should learn - DirectX or OpenGL. Which would be easiest to learn and best to use for a bit of 2D graphic games? I would like to learn to do this for Linux as well in the future (so maybe OpenGL), but if DX is easier to learn then that will do fine.
What do you think?
Also, does anyone know what the original Starcraft uses? And, any links to eBooks or tutorials on the subject would be awesome.