Shadow OS 2008 Mini is an operating system released in 2008 by Unknownsoft Inc. specifically designed to run inside other operating systems, namely Windows and Mac. It is a non-graphical based operating system that runs like a command line interpreter, and processes commands much faster than graphical-based operating systems. Although it can open any file type without an external program, many people do not know how to use it, as it is a text-based OS. Unknownsoft Inc. released a new version (1.3) shortly afterwards that could process service packs in .KTU (short for Know The Unknown, Unknownsoft Inc.’s host website) filetype. The corporation is currently developing Shadow OS 2009, an OS that will be a hybrid of text and graphics.
(From Wikipedia, The Free encyclopedia)