You don't have to write custom shaders for OpenGL 3. Or 4.
Thanks to the Compatibility Profile, you can keep writing old fixed-function code.
Some drivers will only let you use new features if you're on the Core (non-Compatibility) Profile, but since profiles didn't even exist until GL 3.1, you should be safe. The differences between GL 2.1 and GL 3.0 and (relatively) minor features. It's the jump to 3.2+ and 4.1+ that are the big game changers. You ideally should write Core-friendly code these days, but you certainly don't have to.
I can't. In my linux distro
I'll just leave that quote there.
Don't blame linux/Gnu, it's intel's fault!
note: saw a couple of your's presentations in youtube(one of the reasons I came here asking what opengl to use(and still have the same dobut)), very informative.