Free cross platform 2D graphical game engine

Are there any C/C++ free cross-platform 2D oriented graphical game engines (for isometric game)? I'm expecting following features from engine:

• Window creatio开发者_开发技巧n
• OpenGL context creation and initialization
• Resource management
• Animated sprites
• Particle systems

I've considered OGRE (seems to be 3D oriented), Irrlicht (much more than just graphical engine, and also 3D oriented), SDL (only low-level functions, no resource loading/management).

Could you please advise anything else?

Although it's not a full-featured game engine, SFML might suit your needs. Apart from window and OpenGL context creation it also provides 2D sprite functionality. Sprite animation and particle systems are not available out-of-the box but should be easy enough to implement on top of the existing features. Someone apparently already implemented an OGRE-like particle system in SFML.

SFML is distributed under the zlib/png license, which might or might not meet your definition of "free".