Jan Endre Jansen is a map designer and creater. Jansen is best known for founding, designing and creating the Megawad Alien Vendetta with Anders Johnsen. Jansen's portion of this map was originally intended for a project of his own, and was designed in 1998. The castle area in the original map was replaced by the island fortress, which was originally a standalone map designed by Johnsen in 1996. The finally collated work of both Jansen and Johnsen was ultimately rewarded in 2002 and was is included in Doomworld's Top 100 WADs of All Time article.