How do I support different OpenGL versions?

Question

I have two different systems one with OpenGL 1.4 and one with 3. My program uses Shaders which are part of OpenGL 3 and are only supported as ARB extension in the 1.4 implementa

Answer 1

It depends: do you want to use OpenGL 3.x functionality? Not merely use the API, but use the actual hardware features behind that API.

If not, then you can just write against GL 1.4 and rely on the compatibility profile. If you do, then you will need separate codepaths for the different levels of hardware you intend to support. This is standard, just for supporting different levels of hardware functionality.