When I run a fullscreen window (C++ with SDL using the SDL_FULLSCREEN flag), alt-tab has no effect. Researching it, I only found posts of people having problems with it. Is there a way to do it consistently across different machines? (I'm running Ubuntu now, but I'd like portability) Does OpenGL handle this better? (considering switching)
SDL likes to XGrabKeyboard() when fullscreened on X11. This tends to lock out your window manager's hotkeys.
Fix SDL or fix your window manager.