This is a pretty slick web 2.0′ish site that has full api documentation for a collection of programming and markup languages. Next time you’re struggling to remember to, say, set a background color in CSS, try gotapi. It’s not doing anything you couldn’t easily find elsewhere, and in fact many of the api docs for these languages I already have installed thanks to tools like devboi, but they’re all in one place and stitched together with a decent interface.