American writer and librarian whose most famous works include The Official Handbook of the Marvel Universe and the Rook Universe series. His other works include Rabbit Heart and the Lazarus Gray books.
He started working on Marvel Comics' Marvel Encyclopedia series in 2003.
In February of 2008, he published an e-book novella entitled The Bleeding Hells.
He grew up in Milledgeville, Georgia. With his wife Cari, he had a son named Julian.
He and Alan Davis both worked for Marvel Comics.