git-wiki

A wiki engine that uses a Git repository as its data store.

Requirements

more likely to be a bit minimalistic or 'pure' than chock-full of features (no bloat)
html5, no time spent on supporting old browsers
case-insensitive searching. This makes a lot of sense for a wiki, doesn't it?
minimal design
gravatars in page history
the top bar is partly a self-hosted wiki page
attachments might not work :-/
improved recognition for urls
usable on mobile browsers (iphone/android)
use updated or different gems for more extensive markdown-support. (a.o. tables)
no javascript used at this time. (might change in the future)