Elegant, structured XHTML/XML templating engine

 Haml (HTML Abstraction Markup Language) is a layer on top of XHTML or XML
 that's designed to express the structure of XHTML or XML documents in a
 non-repetitive, elegant, easy way, using indentation rather than closing
 tags and allowing Ruby to be embedded with ease.
 .
 It was originally envisioned as a plugin for Ruby on Rails, but it can
 function as a stand-alone templating engine.