How a Computer saved the world
- Article from the American Computer Science Association about the history of Colossus (and IBM's involvement in WWII).
- http://www.acsa.net/a_computer_saved_the_world.htm

Project X: The Colossus Rebuild Project.
- Brief description and photo.
- http://www.project-x.org.uk/bpcollp.html

IEEE Computer Society: Colossus
- Brief description and photos.
- http://www.computer.org/history/development/1940-44.htm

Take a Tour of Bletchley Park
- Information and photos on the Colossus rebuild project at Bletchley Park.
- http://www.lightstraw.co.uk/bletchley/tour.html

Colossus at Bletchley Park
- History and photos.
- http://www.picotech.com/applications/colossus.html

Bletchley Park Museum : Lorenz Cipher Machine
- Descriptions of the Lorenz cipher machine and the Colossus computer built to crack the code. Information on the rebuild of a working Colossus.
- http://www.codesandciphers.org.uk/lorenz/index.htm

Nationmaster Encyclopedia: Colossus computer
- The purpose, origins, and design of the world's first programmable digital electronic computer.
- http://www.nationmaster.com/encyclopedia/Colossus-computer