Henshin uses Tilt to render files and supports all file types supported by it. See the full list.
Files can contain yaml data, it should be at the top of the file and take the form:
---
title: Hello World
date: 2012-05-06
---
Hello, ...
Now in templates it is possible to use title and date variables.
Useful attributes are:
permalink: /feed.xml
none to prevent a
template being used.