What world of warcraft addon is this????

Looking at that picture, it appears to be just a plain Action Bar. After you are logged in, hit the esc on, then the "Interface" on, then the "Advanced options" tab at the top. From there you can check the "Show right Action Bar". You can also add a few other bars around the screen if you want. Once your done with that, you just open your spell book and click-drag them over to the new bar. Hope thats what you needed. Good luck.