From the back of the book:
By the crew at the Unofficial Canon Project Creative Team
The Gamer's Handbook of the Marvel Universe: Deluxe Edition looks to update and expand upon the great works originally presented by TSR in their versions for the Marvel Super Heroes role-playing game. Supplemented by date from the Official Handbook of the Marvel Universe, this presentation has complete game statistics and background information for hundreds of Marvel characters--- the good, the bad and the in-between.
The pages of the Gamer's Handbook of the Marvel Universe Deluxe or MUD, are designed to be placed in a binder and organized as you see fit, adding similar designed pages from other Unofficial Canon Project products, such as the New Marvel-Phile issues and other gaming products produced.
This volume includes updates for familiar characters such as Absorbing Man, Angel, Apocalypse, Baron Zemo, Beast, Black Panther and Black Widow, as well as newer or never covered before characters such as the Acolytes of Magneto, Alkhema, Atom Smasher, Bastion, Bi-Beast, Black Tarantula and Blackheart as well as more than 100 others. Look for more volumes in the near future covering more of your favorite Marvel characters!