As I mentioned above, a window manager does not need to be written to support Xinerama. However there are certain enhancements which window manager developers can do to make Xinerama users lives easier. Features which I thought were desireable include:
* Intelligent placement of windows. Window managers should not place windows in dead areas or across the borders of two heads. New windows should be placed in the current desktop.
* Maximizing windows should maximize the window to the current head only.
* Window Movements should have edge resistance between heads (Much like they have resistance to other windows).
* Dialogs and informative messages should not pop up Between Heads.
I searched the mailing lists, FAQs, and emailed the developers of most of the major window managers to see if they were working on any Xinerama related extensions. The Window Managers/ Desktop environments I reviewed included Blackbox, Enlightenment, KDE, WindowMaker, and XFCE. Enlightenment and Sawfish were the only two which I found significant enhancements for Xinerama. I have detailed what I discovered below.
From their news page: Sun Mar 26 2000
E with Xinerama support
We just got done adding real xinerama support to E this weekend. Now you have edge resistance moving windows between heads, windows will always pop up on the currently focused head (unless it wants to go someplace else by geom settings or you have it saved to go someplace else), maximize (unless you use "absolute" maximize) stays on the current head also. If you have xinerama and you run E out of CVS, test this and give us feedback.
From the Sawfish mailing list I have discovered that they are actively developing Xinerama support. Features which are currently in the development version include :
* Preventing Windows from being mapped across heads * Preventing Windows from being mapped in dead spots * Edge resistance moving between heads * Centered and Random placement modes place windows on the current Head