Vengeance is a full 36-level megawad for Ultimate Doom by Paul Fleschute. With some exceptions, each level is similar in style to the original it replaces, but larger and more detailed. The WAD uses textures from various other projects for a grittier look, as well as music by David Shaw and Mark Klem. Released on March 11, 1999, Vengeance is an improved version of the author's earlier work PSFDOOM. Some of the added levels were contributed by Paul's brother.
The secret level E4M9 is a remake of Quake's E1M2.