I was chatting with teferi the other day:

<gregh> wikipedia needs a 'bisect' operation
<teferi> gregh: gitipedia :)
<gregh> oh, bah. you made me look.
<teferi> nah, it would be a great idea, though
<teferi> don't like what a page says? fork it!
<Nugget> heh
<teferi> an end to edit wars
<teferi> hm
<teferi> I should actually DO this.
<teferi> wiki backed by git repositories

And why not? After all, what is a source control system? It's a way of tracking revisions made by multiple collaborators to a set of text files representing source code. What is a wiki? It's a way of tracking revisions made by multiple collaborators to a set of text files representing web pages. Why do most of the wiki engines reimplement source control?

After a bit of searching, I found ikiwiki which looks like it might be exactly what we are looking for. By setting it up with an SCM as the storage backend, you can edit the wiki offline, or edit it using your favourite text editor, or use your SCM features like branch, merge, blame, etc. Must investigate further and set up an ikiwiki to try.