This is a wiki engine written in Clojure that uses git as the document store and version tracker, and Markdown as the template language.
I wrote this as a way to learn Clojure, and to see how well git would work as a wiki backend. The answer: it works fine, though I'm unsure about how well it would scale. In particular, generating document history pages requires some potentially expensive operations with the clj-jgit API as it is.
The project is currently abandoned. If you really want a Markdown-based wiki that leverages an SCM as the document backend, just use Fossil :)