XCube is a basic command line interface, with support for files, user accounts(only in the GUI), and variables(only in DevMode). It is developed in C#, using the Cosmos Kernel, which was heavily modified by me to suit my needs.
XCube is not meant to be any kind of replacement for any OS. I just treat it as a fun weekend toy to play with when I have the time. Folder support should be coming soon, and please check out my personal site xcubedev.wikispaces.com! Thanks!