Holocaust Denial on Trial - Comprehensive site on the Irving-Lipstadt/Penguin libel trial, compiled by the defence. Includes court transcripts, expert testimony and analysis of the trial.
Holocaust History Project - Essays, and reproductions of documents, which expose and debunk the claims of Holocaust deniers. Includes over 1,000 pages from such sources as the International Military Trial at Nuremberg, and documentation of homicidal gas chambers.
Jewish Virtual Library - Holocaust Denial - An overview of Holocaust revisionism, describing the major groups and individuals involved with that movement, and presenting rebuttals to common revisionist claims.
The Mad Revisionist - Parody of the common claims made by Holocaust revisionists.