HAML (HTML Abstraction Markup Language) is a templating system designed to avoid writing inline code in a web document and make the HTML cleaner.

HAML is based on one primary principle: markup should be beautiful. It's not just beauty for beauty's sake either; HAML accelerates and simplifies template creation. The end result is beautiful, DRY, well-indented, clear markup. HAML also follows the 'don't repeat yourself' principle which aims to reduce repetition in code.