It is distributed under the terms of the GNU General Public License (GPL).

Early versions of the Hurd were developed on top of CMU's Mach 3.0.

The first ChangeLog entry by Thomas Bushnell (rather than by a Utah researcher) is from 16 December 1996.

[3][4][5] In 2002, Roland McGrath branched the OSKit-Mach branch from GNU Mach 1.2, intending to replace all the device drivers and some of the hardware support with code from OSKit.

After the release of GNU Mach 1.3, this branch was intended to become the GNU Mach 2.0 main line; however, as of 2006, OSKit-Mach is not being developed due to lack of activity in OSKit itself.