Xsun & Xorg in Solaris currently support the Xinerama extension, but the libXinerama
client library needed for clients to query the extension to get physical screen
boundary information has not yet been shipped. It should be.
An ARC fasttrack has been filed for this - the library will be integrated once that is
approved: http://www.opensolaris.org/os/community/arc/caselog/2007/135/