Allright so I've been doing some searches, here what I got:
SDL: It is a standard, very mature but very old. (I got posts of late 2009 where they were still waiting for the 1.3 to come up...we are still waiting 3 years later). Also it seems abandoned and old style (it's around from the '98). And also it's made in C (for this there's no downside nor upside. Someone prefers C over C++ nowadays for some reason and C can run on C++ but not viceversa).
SFML: It's a new born in the libraries. It's not very mature and lack of a lot of documentation. It was buggy till 1.6 but now the 2.0 is quitely good (it's the one I've tried). It has a lot of things built in (even the possibility to easily use OpenGL). It's in C++ and has the OOP paradigm.
Allegro: I haven't heard much about it. It gives me the idea of a toy, but it's not an opinion I count on. It is C based (like SFML) but doesn't have that large community (like SFML).
I'm considering only cross platform libraries. Now I'd like to make few questions about this situation:
- Is SDL falling apart?
- Why isn't SDL being update to the so awaited 1.3 (which will, they say, support iPhone and phones) in 3 years?
- Is SFML gonna take SDL place?
- Why people say that SFML is more abstract then SDL? It seems pretty much the same to me. You have likely all the configurations you want on both.
- Allegro had a troubled story. It was only for DOS, then it was ported for other platforms etc... Is it really cross platform?
- How stable is Allegro?