The X Window System was created in the mid-1980s at the Massachusetts Institute of Technology. In 1988, MIT formed a member-funded consortium to provide the technical and administrative leadership necessary to support further development of the X Window System. In 1992, MIT and the membership decided it was in their best interests to move the consortium out of MIT and create an independent, stand-alone organization. All rights to the X Window System were assigned by MIT to X Consortium, Inc. on January 1, 1994. On December 31, 1996 the X Consortium, Inc. closed its doors and all rights to the X Window System were assigned to The Open Group (then known as the Open Software Foundation).
The X.Org Foundation's public ftp site is ftp://ftp.x.org/
Information about the X.Org Foundation git repository is on the X.Org web site at http://www.x.org/wiki/Development/git