Alan Coopersmith on behalf of Sun Microsystems has announced this afternoon that they will be relicensing all of their past and present X server work under the canonical form of the X.Org license in its latest form. This is being done to reduce the number of MIT license variants within the X Server. This isn't a major change and will not negatively impact users but simplifies and improves the licensing to some extent. Sun has been pushing code into X11 for over 21 years with their copyright touching hundreds of files in the X Server.
The standard X.Org MIT license along with the Sun Microsystems version can be found in the COPYING
file. The Sun announcement was made on xorg-devel