.HAML File Extension
What is a HAML file?
Source code file written in Haml, (HTML abstraction markup language); stores a template written in Haml language that is used to generate the HTML of a web document; can be used to replace Ruby template scripts (.ERB files) with its abbreviated syntax.
One prominent feature of Haml is that it replaces conventional tags (<>) with the percent sign (%) in order to save time and appear “cleaner.”
An example of simple Haml language and the HTML language generated through the template engine:
%h1 My First Heading
<h1>My First Heading</h1>
NOTE: You can switch over from ERB to Haml by replacing the "erb" file extension on ERB files with "haml.”