During my poll of developers about their Bugzilla settings, I was told that the current maintainers of the following two extensions do not have time to take care of them any longer and they need someone to step up and maintain them:
EasyTimeline APC
For what it is worth, EasyTimeline is deployed on WMF wikis (See http://hexm.de/58 for an example from mlwiki).
Thanks,
Mark.