Vrack is a single level PWAD for Doom II released on November 12, 2000 by Fredrik Johansson. It requires a Boom compatible source port. Vrack is set in a tech base floating somewhere in outer space, inspired to some degree by Dark Forces and also MAP04 of Dystopia 3 (which uses the same music, borrowed from Descent). Vrack was followed by the similarly-styled Vrack 2 and Vrack 3. The level contains a reference to Hissy in one of its secret rooms.