Sassy for Umbraco Sassy for Umbraco allows you to create, edit and delete SASS files for your Umbraco website. The package installs a custom tree allowing you to create and edit SASS files directly inside Umbraco, which compile down to CSS files. The editor has support for SASS and gives compiler error messages if there any, allowing you to fins the issue easily with your SASS file. What is Sass? If you are a front-ender, then you will love Sass its a pre-compile for CSS allowing you to create functions, introduce variables and nest your CSS to geenrate nice and neat CSS.