The software is called plazmic. Once downloaded it comes with a composer and a theme builder. If you have any problems with building or to get the basics for theme building just click help in the application. Theres alot of useful info there. Also check the developers forum for other issues you may run into. Go to plazmic.com for the download.
I would do a lot of searching through the threads and reading first. just search "how to make theme" or even just "plazmic". There's a LOT to do and know so you should be armed with the basics when jumping in a project like theme making. Best of luck!
