That CrypTool was originally designed as an internal business application for information security training. CrypTool has since developed into an important open-source project in the field of cryptology. Over 50 volunteer developers worldwide contribute to the program.
"CrypTool includes an unparalleled array of cryptologic tools, which are ideal for anyone who wants to study cryptography or cryptanalysis. CrypTool is a free application, readily available on the Internet."