Nupedia
Nupedia is Wikipedia's predecessor. It was, compared to Wikipedia, a failure, largely because it was not open enough to editing by everyone (or almost everyone). Wikis such as Citizendium that have been patterned after Nupedia's approach have met similar fates. The example of Nupedia is important to remember when people suggest "quality control" measures that focus on making bad edits hard to make. "The wiki way" is to instead make bad edits easy to correct by attracting and cultivating a community of editors, any of whom can revert a revision that degraded the quality of the wiki.