Sass in itself is more like a kind of program that compiles SassScript into actual CSS. So although the language itself is SassScript let’s oversimplify this and postulate that Sass is an interpreted scripting language.
Reference:
Web: http://www.sitepoint.com/compass-sass-jquery-javascript/

libsass is the lib and sassc to execute it. 

Verify tapped taps:
$ brew tap

Untap the unnecessary taps:
$ brew untap homebrew/versions

Update LinuxBrew:
$ brew update

$ brew search sass
Output:
libsass  sassc
Or use:
Go to http://braumeister.org/browse/s/8

Run doctor the perform a clean installation:
$ brew doctor

Run the formulae installation:
$ brew install libsass sassc
Output:
[...]
==> Installing dependencies for libsass: autoconf, automake, libtool
[...]
==> Summary
/home/esteban/.linuxbrew/Cellar/libsass/3.2.5: 13 files, 7.1M, built in 4.6 minutes
[...]
==> Summary
/home/esteban/.linuxbrew/Cellar/libsass/3.2.5: 13 files, 7.1M, built in 4.6 minutes

Verify the new formulae installation:
List installed formulae:
$ brew list

To upgrade packages:
$ brew upgrade <FORMULA>