... is retired.
(Underscores, if you don't know it, is a completely awesome starter theme for WordPress.)
Underscores now includes Sass files out of the box; to use them, go to http://underscores.me and grab a fresh copy of the theme. You'll find the "Sassify" checkbox under the Advanced Options.
With that, there's no need to maintain this as a separate fork. So long and thanks for all the (Sassy) fish!