Most Linux users are aware that dealing with full-screen windows on X11 can be a mess, especially for games. There's issues pertaining to changing the resolution for gaming, the current full-screen window manager hint not being incredibly clear, and other problems. Ryan Gordon writes in his new proposal, "I've been doing Linux video games for over a decade now, and we've never really had a satisfactory means to handle fullscreen games on X11. I see this mailing list discussed fullscreen problems briefly in February, but I wanted to make a formal proposal of how the system should handle applications that want to 'go fullscreen.'"
The proposal is to come up with a _NET_WM_STATE_FULLSCREEN_EXCLUSIVE window manager hint that works out the shortcomings of the full-screen hint used currently by most games, _NET_WM_STATE_FULLSCREEN.
Ryan and Sam have already worked out an initial patch for the SDL library to use this new hint but they haven't tried hooking in the support to any window manager yet.
Those interested in the specification and low-level technical details about this proposal, all of the information is available from this mailing list message.
One of the changes is that games (or other software using this exclusive full-screen hint) would make the request to the window manager to change the resolution if needed, rather than tapping RandR, XVidMode, or other interfaces directly. However, not everyone is fond of this proposal. Martin Gräßlin of KDE/KWin already wrote, "we (KDE window management) actually hate that games change the resolution and I don't think that moving the responsibility to the window manager will solve anything." He backs up his dissenting opinion about KDE specifics for why he doesn't like games changing the desktop resolution.
This mailing list discussion has just started so check back on the thread for the latest feedback to Ryan Gordon's WM proposal.