Refills, by Thoughtbot, are prepackaged patterns and components for websites, built on top of Bourbon, Bitters, and Neat. If you code websites, you need to check these out. From proper sliding menus to grid items, heroes and accordion tabs, every Refill looks incredibly well done and impressive. The list includes more than 20 commonly desired website patterns or components which are simple in idea, yet tricky to implement.

The whole thing is open source. Great resource.