There are a couple of ways to start using Sass:
1. Applications : There are a good many applications that will get you up and running with Sass in a few minutes for Mac, Windows, and Linux. You can download most of the applications for free but a few of them are paid apps (and totally worth it).

2. Command Line : In Linux:
If you're using a distribution of Linux, you'll need to install Ruby first. You can install Ruby through the apt package manager, rbenv, or rvm.