Someone has created a Windows-based simulator of the German Engima machine.
This software is an exact simulation of the 3-rotor Wehrmacht (Heer and Luftwaffe) Enigma, the 3-rotor Kriegsmarine M3, also called Funkschlussel M, and the famous 4-rotor Kriegmarine M4 Enigma cipher machine, used during World War II from 1939 until 1945. The sim has a very authentic feeling with its hands-on approach: you can select between the three models, actually lift out and insert different rotors, adjust their ring setting and set up the plugboard. The internal wiring of all rotors is identical to those that were used by the Wehrmacht and Kriegsmarine. This simulator is therefore fully compatible with the various real Enigma models and you can decrypt authentic wartime messages or encrypt and decrypt your own messages.