Anyone know how the folding sidebar menu is done?

Its a nice effect.

Note only does the menu fold out, but when you ask for source, it folds out some more.



As I noted in
another thread
asking the same question:

It’s done with just CSS, using animation with transform properties. The animation is started by changing some style elements in the source code container. To make it look like a book, the source code is actually cloned to appear in two elements, with the other (animated one) showing the left side and the other showing the right side. There’s negative margins, absolute positioning, clipping (overflow: none), and so on. You can use Firebug or built-in browser inspector to examine the elements and CSS.