Is it just me or none of the flipping WE are able to minimize my Open Arena or Alien Arena window for me to take a peak at my desktop, e.g. ALT + TAB on Winblows? I tried metacity/xfwm4/kwin and all of them have shortcuts for window minimization e.g. ALT + F10 but when pressed the 3D apps ask me if I want to exit out of the game or they don't do anything at all.
The problem in actually lies in X, while it could in theory be possible to have minimization handlers in SDL, GLX and GLUT are a whole other story. I remember some GLX applications were able to be minimized with ctrl-ESC (IIRC), but GLUT is a complete different beast in itself, and handles the window independently of the rest of the system... Still sits atop X, but handles X differently than your WM does.