The Ism Book is an intellectual "field guide" that provides brief definitions of theories, doctrines, movements, and approaches in philosophy, religion, politics, science, the arts, and related disciplines. It was originally written in 1990 and was first posted on the web in March 1996. In 2005 it was totally revised and nowadays it is continuously updated on the web by Peter Saint-Andre, who has placed it in the public domain. Feedback is welcome via email or IM, the XML source code is available as a tarfile or zipfile, and changes are announced via Atom and RSS.