Tor Books is an imprint of Tom Doherty Associates, LLC which publishes popular fiction, and is particularly noted for its science fiction and fantasy titles. Tor publishes mainstream fiction, mystery, and occasional military history titles under its Forge imprint. Tom Doherty Associates, LLC, was formed by Tom Doherty in 1980, and sold to St. Martin's Press in 1986. Along with St. Martin's Press, Henry Holt, and Farrar Straus Giroux, it is now part of the Holtzbrinck group.
Harry Turtledove has published several books through Tor, including the Darkness series, the Crosstime Traffic series, and The Gap series.