Which OpenGL extensions are most likely available on most computers right away?

I was wondering which OpenGL extensions are available on the most basic PC’s that just have the Intel graphics chipset/driver? I am just trying to figure out which exensions you can assume most Windows operated computers have.

It depends on the Vendor. If you want to write only one renderpath for all cards, you will be stuck to the ARB_Extensions.
There is no Intel graphics driver with basic functionality. If you want to write for all cards use the extensions that come with OpenGL 1.1, 1.2 or 1.3 because most of the cards out there support them.
Try not to care what happened before OpenGL 1.1, you will have to set a startingpoint (TNT2-level Hardware is not bad, because of the stencil) or you will only be able to use OpenGL 1.0.

cu
Tom

www.delphi3d.net
-> hardware info (or something like this is the topic called)