Hacker CMS

 Hacker CMS  is a Markdown-based web site editing and publishing app project built on top Jekyll, Ace, and jsTree that can be installed on Sandstorm.

Author:
 * This app was stiched together over the course of one day by Kenton Varda.

Open source:
 * https://github.com/kentonv/ssjekyll

IndieWeb support
There doesn't appear to be any support (yet) of various IndieWeb building blocks such as microformats and webmention.
 * Issue 3: feature request: webmention receiving (and display of comments, likes, reposts) support

Examples
Example uses of Hacker CMS:

Sandstorm Official Blog
The official Sandstorm.io blog uses Hacker CMS. E.g.
 * https://blog.sandstorm.io/news/2014-07-21-open-source-web-apps-require-federated-hosting.html