Spacer Dreams (1995)
The Four Magics (1996) (with William R Forstchen)
Alien Dreams (1997)
Wizardspawn (2003)
Nightmare Logic (2004)

Great Cat Mysteries (1996) (with Joan Hess and Sharyn McCrumb)

Net Force (with Tom Clancy and Steve Perry)
8. Changing of the Guard (2003)
9. Springboard (2005)
10. The Archimedes Effect (2006)

Cat Crimes (with Ed Gorman and Martin H Greenberg)
Cat Crimes for the Holidays (1995)
Cat Crimes Through Time (1999)

Fantastic (with Martin H Greenberg)
Spell Fantastic (2000)

Murder Most... (with Ed Gorman and Martin H Greenberg)
Murder Most Feline: Cunning Tales of Cats and Crime (2001)

First Contact (1987) (with Martin H Greenberg)
An Anthology of Angels (1996) (with Martin H Greenberg)
Future Net (1996) (with Martin H Greenberg)
Battle Magic (1998) (with Martin H Greenberg)
Far Frontiers (2000) (with Martin H Greenberg)
Guardsmen of Tomorrow (2000) (with Martin H Greenberg)
Past Imperfect (2001) (with Martin H Greenberg)
Silicon Dreams (2001) (with Martin H Greenberg)
Future Wars (2003) (with Martin H Greenberg)