Sass is bundled with Haml, so to get it you’ll need to install Haml as well.

Standard Gem

Most people will just want the standard stable Sass gem. To install this:

gem install haml

haml-edge Gem

To get the latest and greatest Sass goodness, though, you’ll need something else. A haml-edge gem is created automatically every time changes are made to the master branch. To install it:

gem install haml-edge

Note that gem "haml-edge" must be used before require 'sass' if haml-edge is to be used.

Installation from Git

Haml can also be installed directly from the Git repository:

git clone git://github.com/nex3/haml.git
cd haml
rake install

Downloadable Archives

Finally, archives of current and old releases are available on Rubyforge.