Ubuntu unveils its next-generation shell and display server

Actually, come to think of it I KNOW the fullscreen thing can be forced, as kde 4.10 now includes a kwin scripting ability, with one of the two shipped scripts being a "video wall" script that forces selected media app windows to fullscreen to all monitors instead of just one, when they go to fullscreen mode. So it could certainly deny fullscreening at all, as well.

(Of course kde being kde, the activation of this script is a configuration option. FWIW, I turned off the other script, but like this one enough to have patched it to apply to smplayer2, it applied to smplayer, vlc, and one or two others, originally, but not to smplayer2 without the patch, which here on gentoo I apply by simply dropping it in the appropriate /etc/portage/patches/ subdir so it's applied each time I update the app. I should submit it upstream, but I already submitted patches for superkaramba that have just sat on the open bug, no comment or any indication at all that anyone's even read them since I submitted them for 4.5 or whatever, thus years ago. That tends to be a bit of a disincentive to even bother filing any further kde patch-bugs. =:^( )

So sometimes the window manager /does/ at least redefines "fullscreen" to suit its own purposes. =:^)