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.

>>11
Because different graphics adapters and operating systems prefer different endianness.
What a retards designed them? RGBA should be standard, like in SVGA.

You really should use each platform's preferred windowing toolkit (Xlib, Windows API, Cocoa) and OpenGL.
These aint portable and hard to use. I want a dumbed down API, which gives me a pointer to framebuffer + keyboard scancodes, just like in good old DOS times with 0A000h

I think DOS had the best API possible. No stupid memory protection, windows or toolkits, just raw machine power.