I don't know what happened, but these 2 disappeared froim my previous reply :
Sass and Compass do not automatically mean responsive design. You can also do responsive design in CSS3 (or JavaScript God forbid).
They are just tools to make the responsive design. If you already know how to make responsive designs in one, you can also do it in the others. You would just have to become fluent in the other tool(s).
If you're new to responsive design, you're better off with a detailed tutorial, or a good book.
I found the book "Responsive Web Design with HTML5 and CSS3" by Ben Frain very good at explaining this subject.
In the book the author only casually refers to Sass and Less as better options than CSS3.