This brings to mind the X session management protocol (http://en.wikipedia.org/wiki/X_session_manager) that never seemed to be used be in modern Linux applications. Issues that others brought up regarding memory consumption could be addressed with more consistent use of this or a similar protocol. While intended for saving state on logout, there's no reason the window manager/session manager/something else couldn't just direct an application in the background to save state and then kill it when memory gets low. That said, it's probably a bit too late in the game to establish such a policy. Users would be more likely to blame the desktop environment for killing the program and losing all of their work instead of blaming the application for not saving the state to begin with.