Alright that is mazzleui,why do I know this well it's cause I use it myself and let me tell you this is a really great ui and has some really cool features.it can be found here:
http://www.wowinterface.com/downloads/info7833.html
Just follow the set of instructions under:
Steps for installing MazzleUI with my Addon Pack are as follows:
it leaves out the step telling you to load out of date addons though. To do that, before you log in, at the char select screen, in the bottom left is a button called AddOns. Click that and a window pops up, in the top right of the window is a checkbox for load out of date addons, check it, hit ok and your good to go.