That's the Saab LX design by Sixten Sason, circa 1941. There was an article on it (where the drawing undoubtedly originated) in the August 1998 issue of Aeroplane Monthly. Supersonic, turbojet with liqquid rocket, supersonic and armed with 12 photocell-guided rockets.
A suggestion, however: take references from unicraft with some skepticism. For example, on their "German future releases" page, they show this:
And call it a "German VTOL Project."
ERRRRR. Wrong. It's an *American* VTOL project, patented by L.H. Leonard... filed in 1943, granted in 1949. It preceded the German Triebflugel. See it here:
http://www.google.com/patents?vid=USPAT2479125&id=o59xAAAAEBAJ&dq=2479125&num=100