OpenGL newbie seeks help!

Hey /prog/, I'm writing a cross-platform OpenGL application which does some off-screen rendering. I've found two ways of doing that - with pbuffers and with FBOs, the latter is preferable. I want old videocards to be supported too.
Now tell me, which technique should I use? Do the older videocards support FBO? Do they support pbuffers?
Thanks.

>>15
You have to agree, the past was much nicer and newbie friendly.
I agree with the latter. I would argue that the present is nicer because it lets you do more and many things (i.e. scrolling, blending, rotozoom, 3D, etc.) are easier.

What if I just want to put some pixels on screen and dont care about windows/double-buffering/modesetting/context and other bloated crap?
I honestly don't know. There's a bunch of stuff like SVGAlib and DirectFB but I doubt it's well-maintainted, well-engineered and as lean as real mode. If I were you I would probably write small operating systems or use DOSBox.

>>17
The state of the art of direct framebuffer access is to render everything in CPU memory and then copy it to the GPU for scan-out.