It needs php but no database.
When I use git in this sense, I'm talking mostly about version control and backup.
I'm not convinced I would benefit from the full hyperlinked format a wiki would provide, since it would require a concerted effort to organize things well. I usually just throw crap into text files and use grep to find stuff later.
http://onethingwell.org/post/457674798/a-poor-mans-notationa...
I'm using a slightly hacked version of this on the main PC
There should be no infrastructure requirements as far as I can tell (just downloaded it, gave it a spin). It's a single file, just like your current stuff. Granted, I don't know about the possibilities to recover data in cause of trouble yet, but you need nothing but a browser and can share/sync it just like your current system.
https://git.wiki.kernel.org/index.php/Interfaces,_frontends,....
Mainly I've kept most of my programming notes, records, todos, research and so on in flat text files. They are easy to view, edit, backup, exchange, copy from, and version. For my use cases, I find it a more appealing technical solution to a wiki, which requires infrastructure to back it.
If someone could come up with a git/wiki hybrid, that would be interesting.