The GNU Manifesto was written by Richard Stallman at the beginning of the GNU Project, to ask for participation and support. For the first few years, it was updated in minor ways to account for developments, but now it seems best to leave it unchanged as most people have seen it.
The GNU Manifesto (http://www.gnu.org/gnu/manifesto.html)
The gnu is a large hooved mammal of the genus Connochaetes[?].
The original announcement was followed by Stallman's "GNUManifesto" and other essays that laid out his motivations for the GNU project, one of which was to "bring back the cooperative spirit that prevailed in the computing community in earlier days".
In the GNUManifesto, Stallman had mentioned that "an initial kernel exists but many more features are needed to emulate Unix." He was referring to TRIX, a remote procedure call kernel developed at MIT, whose authors had decided to distribute for free, and was compatible with UNIX version 7.