jquery - What did StackExchange use to build to popup like dialog when you click StackExchange in the Top Left? -

On the stack overflow, when you click "StackExchange" on the top left, it opens a dialog like popup Does anybody know what they use to make or what kind of jQuery plugin makes such a UI?

This is not needed from a plugin copy when you click on the link Check the firebug can contain feed one div containing content, it is very good to determine how things are made.

Especially for this link, it seems that most of the work is CSS.