A WikiHive is like a WikiFarm, with the difference that instead of creating a bunch of separated and isolated wiki, a WikiHive seeks to assemble Wiki into a collective, where all interact in unison. The first known WikiHive is the TaoRiver wiki, set up in early 2004, which includes the PlogDev?, SymbolProject, WikiFutures?, and VisualWiki.
Are the various wikipedia projects, like wiktionary, and what not, also a wiki hive?
See http://wikiindex.org/Category:WikiHive (was: http://www.worldwidewiki.net/wiki/WikiHive ; this link currently broken:403) for a list of all known public wiki hives.