Works with HTTP and possibly HTTPS Subversion repositories. See the SVNStorageRationale.
SVN integration is thanks to SVNKit, the Java svn client implentation used by Subclipse. There's probably no reason why we couldn't support other repository types too as SVNKit has an interface that hides all that.
Pages are svn locked during edits as there's no straightforward way to handle conflicts of paragraph (rather than line) based text.
The somewhat pretty diffs are generated by diff_match_patch.
A Lucene search index is updated on page change and is used both for search and finding backlinks.
For all the things it doesn't do yet see TodoList.