Century Next Door series

• Orbital Resonance (1991)
• Kaleidoscope Century (1995)
• Candle (2000)
• The Sky So Big and Black (2002)

Thousand Cultures series

• A Million Open Doors (1993)
• Earth Made of Glass (1999)
• The Merchants of Souls (2002)
• The Armies of Memory (2006)

Time Raider series

• Wartide (1992)
• Battle Cry (1992)
• Union Fires (1992)

Timeline Wars series

• Patton's Spaceship (1997)
• Washington's Dirigible (1997)
• Caesar's Bicycle (1997)
• Timeline Wars (1997) (omnibus volume)

Jak Jinnaka series

• Duke of Uranium (2002)
• A Princess of the Aerie (2003)
• In the Hall of the Martian King (2003)

Directive 51 series

• Directive 51 (2010)
• Daybreak Zero (2011)
• book 3 - unknown title / publish date

Other

• The Man Who Pulled Down the Sky (1987)
• Sin of Origin (1988)
• Mother of Storms (1995)
• Encounter With Tiber, with Buzz Aldrin (1996)
• One For the Morning Glory (1996)
• Apostrophes and Apocalypses (1998) (collection)
• Finity (1999)
• The Return, with Buzz Aldrin (2001)
• Gaudeamus (2004)
• Payback City (2007) (thriller, written in 1997, self-published e-book)
• Tales of the Madman Underground (2009) (non-genre novel, a Michael L. Printz Award Honor Book)
• Losers in Space (scheduled for 2011)

• Nebula Award Best Novel nominee (1992) : Orbital Resonance
• Nebula Award Best Novel nominee (1993) : A Million Open Doors
• Hugo Award Best Novel nominee (1995) : Mother of Storms
• Nebula Award Best Novel nominee (1996) : Mother of Storms
• Michael L. Printz Award Honor Book (2010): Tales of the Madman Underground: An Historical Romance 1973