Craig Hanley's Gerry Mulligan Page: Fan page covering recording history including musicians, discography, cover illustrations, slide show and sound clips.
DownBeat.com: Gerry Mulligan: Features a biography, a classic article, discography, and photos.
The Gerry Mulligan Home Page: Fan site features biography, discography, recommended listening, and profiles of over 180 of his sidemen and collaborators.