How to make an announcment box with Twitter bootstrap?
 

I have it on a site anyway, and thought why not use it to make the announcment box.
But don't really have idea how to do it?

Infact I'm not even sure if it's a CMS or just a library of fancy css, fonts and images?

You can use the Modal effect! i can't add the Code over here but you can check for this effect!