Which toolkit should I use: gtk2+ or gtk3+?

Hi,

I was writing a program (about 500 lines) that makes use of some old openGL 2.1 graphics using C and freeGlut. The reason I used openGL 2.1 is simple: most tutorials on the net refer to it. Then I realized it would be better to include a GUI, so having the code written in C, I can only go for GTK. But then there is the problem: GTK3+ does is incompatible with openGL2.1 code (halting problem : Using OpenGL with GTK+ ). So I would need to go to GTK2+. But going to GTK2+ is going backwards is it not?

What do you guys recommend? Here are a few options:

1) Should I learn new openGL and use state-of-the-art GTK3+

2) Just learn GTK2+

3) Well, just convert/rewrite your C code into C++ and use Qt as it is cross-platform (GTK3+ is not so great in that aspect) and can achieve some wonderful results.

OpenGL 2.1 is old, if you're okay with using it still, why wouldn't be okay with using the old GTK as well?

Agreed with Yarin, if you want to stick to C and an old OpenGL version, then just go with GTK2+, it's perfectly fine and not "old" in any sense of being bad / redundant.