HarperCollins
In the U.S., the publisher of Terry Pratchett's Discworld full length novels and children's series, and Paul Kidby's The Art of Discworld.
In the U.S., most other "Discworld miscellaneous books" such as the Mapps, other art books, the Companion, the Science books, and the play text by Stephen Briggs are directly imported from the U.K., with no U.S. publisher or printer.
HarperCollins is also now (2006) the U.S. publisher of Good Omens, which in the U.S. was previously published by The Berkeley Publishing Group, a division of Penguin Putnam Inc.