I should perhaps add that even with a mod_xinerama and _any_ reasonable effort, Xinerama will still have serious problems, at least with programs that try to position their own floating windows, and possibly also ones that use crappy methods to look up windows. The former simply is not doable without updates to the ICCCM to be aware of nested WM window configurations. Currently the ICCCM does not specify how applications should handle multiple levels of WM windows, but also does not disallow it. So one app handles that one way, and another the other way.
It is not reasonable to not have the confusing "virtual root windows" for each physical screen if you want the workspaces on each screen to be separate for floating windows, the windows that this problem mostly affects. And if you don't want them to be separate, you don't really need Xinerama support. Configurations with screens of totally differing sizes appearing as one are absolutely stupid (but so is multihead in general, most of the time). Hence, Xinerama is a mostly useless piece of crap of an extension. You either don't really need the information, or you'd simply want plain old X multihead with window migration between screens, something that is only _artificially_ restricted when the bit depths are the same. But the general trend among the X folks is to write crappy mutually incompatible extensions for everything, instead of extending the X protocols. (There's _no_ need for Xrender, Xft and that shit. It would've been sufficient to add extra transparency and blurring bits for programs to set when they can cope with that stuff, and use the old stuff.) -- Tuomo
