I'm familiar with OpenGL 1.x. I typically use SDL with OpenGL 1.4 on Linux, and I've never run into problems, even on my modern system.

I've read on the OpenGL site about deprecation and compatibility contexts, but I'm still unclear as to whether it's safe to continue to use old versions of OpenGL, as opposed to using old features in newer versions.

When functionality is marked deprecated ... future versions of OpenGL may remove it.

Does deprecation simply imply that those functions can't be used alongside newer features?

More specifically, are there any systems today (other than embedded) where OpenGL 1.x isn't available? The old-skool stuff like, glBegin, glEnd, glDrawPixels, etc.

Note: I'm not a professional games developer, so you'll have to excuse my ignorance. I'm working on a mostly 2D game that I would like to keep multi-platform, supporting at least Linux, Mac, and Windows.