The darcs revision control system has all but lost out to git within the past few months. A rather large part of the reason is a rushed and very poorly worded release announcement, following a rather long (I'm told 4 years; I haven't been aware of it that long, which itself is perhaps ominous) post-1.0 silence from the darcs developers:

Even people who are familiar with internal politics may not realize the extent to which technical decision-making can be a distant second, or worse, to political concerns. An extreme case is real politics: