rEFInd is a boot manager that works with PCs and Macs, and is able to boot virtually all modern OSes. It features many improvements over native bootloaders and it is highly configurable.
For more information on how to install and configure rEFInd please visit rEFInd's homepage http://www.rodsbooks.com/refind/
This theme is very unorthodox. rEFInd has its theming limits and such boot menus are simply not possible using the conventional rEFInd theming options.
The icons of the theme are drawn from the background image (including drive "icons", in this case Psi gauges) and the drive icons are transparent images. Images of selection are used as overlays that superimpose on the background.
The downside of this kind of theming is that the UI is "hardcoded" to a predetermined number of drives. Of course you still can boot any bootable media inserted normally, but the whole thing gets shifted and it won't look good.
This is not a problem for me as 99.9% of the time I only have these three boot options (OSX Windoze and Linux). It shouldn't be a problem for most.
The theme's resolution is 1280 x 800 but one can easily mod it to other resolutions using some graphical editor. PSD "template" files are included.