The GFDL corpus is the corpus of all materials released under the GNU Free Documentation License. It includes all the Wikipedias, Wiktionary and other projects over which Wikimedia claims editorial jurisdiction. It also includes many that are not under supervision of these people.
There is some controversy over how much influence Wikipedia:Itself should exercise over the corpus and whether, given its central position relative to other access providers, and its claims to be encyclopedic, it has special responsibility to avoid applying arbitrary criteria to its editorial decisions.
While GNU itself considered a GNUpedia it has generally withdrawn from this effort to support Wikipedia. However it is not clear that it has acceded to standards set by the Wikimedia Foundation re: which edits or which contributors should be supported or not:
The terms of the GFDL itself are quite clear that any improvement to the corpus must be made available to all. This seems at present only practically possible via edits to the Wikipedia and related projects. In this view, Wikipedia violates GFDL by refusing any encyclopedic edits based on ad hominem or other sorts of factional or personal arguments. This has been a major source of controversy among the various open content efforts including Wikinfo, Consumerium, Disinfopedia and Wikipedia:Itself, all of whom have quite different standards - but of which only Wikipedia claims the right to apply strictly ad hominem rules to determine who edits.
The matter has yet to be tested in court.