This X11 windowing feature enhancement is new in the Solaris Express 3/06 release.
The Xorg X Server for x86 and x64 platforms has been upgraded from version 6.8.2 to version 6.9 by the X.Org Foundation and the open source community. The new version adds support for more graphics devices including new models from ATI, XGI, VIA, and Intel. The Xorg X Server version 6.9 also adds keyboard and mouse handling improvements, performance enhancements, and bug fixes.
For further information, see the Xorg(1) man page.