What versions of OpenGl are supported?
IIRC SFML is built for OpenGL' core profile 2.1, you can also just search for it, there should be some answers.
From there on you can use anything that's higher, as the documentation states:
OpenGL versions above 3.0 are supported by SFML (as long as your graphics driver can handle them), but you can't set flags for now. This means that you can't create debug or forward compatible contexts; in fact SFML automatically creates contexts with the "compatibility" flag, because it uses a few deprecated functions internally. This should be improved soon, and flags will then be exposed in the public API.
What is the binary size of SFML in a built application (with only the modules that are used for windowing, graphics and input)?
Depends on how you link SFML, what compiler you use, for which platform you build, etc.
If you link statically and your compiler is smart enough it would really only include the symbols that are used by your code. If you link dynamically it you'll have to ship the full dlls. x64 binaries are often bigger than x86 ones etc.
Not to forget that you could use some an compressor in the end to shrink the binary even further.
So overall I can tell you that your assets will most likely turn out to be way bigger than your binary.
One last favor, can you guys provide some references on what was SFML used in(commercial)? I'm searching but I really don't want to miss anything important.
There are a lot of projects out there with SFML (e.g. see my
SFML News), commercial games are rare but that's mostly because SFML is relatively young and people tend to use what's older and "more established", so I think this should really not be something to measure SFML's "success". You can find a few by
BLENDO Games (Atom Zombie Smasher & Air Forte, maybe others).
