Palaround - Meet people you should be friends with.
Sass - Syntatically Awesome Style Sheets
Digg - Digg delivers the most interesting and talked-about stories on the Web right now.
PostCSS - Increase code readability. Add vendor prefixes to CSS rules using values from Can I Use. Autoprefixer will use the data based on current browser popularity and property support to apply prefixes for you.
quippd - quippd is a social news site that anyone can edit.
Stylus - EXPRESSIVE, DYNAMIC, ROBUST CSS