Hardware, Extensions, User Contributions, Other Support Sources, Etc.
Oscar, DJ0MY, offers a hardware kit, utilizing an Arduino Nano (user supplied). The kit features a speed potentiometer, opto-isolated TX and PTT outputs, three memory buttons, and a PS2 keyboard connector. Oscar provided testing, especially for the K1EL Winkey interface protocol emulation, and numerous development ideas.
Dietmar, DL2SBA, has created some extensions to the hardware, including button switch banks.
Marc, F6ITU, has created a Wiki page (En Francais) describing the keyer project and plans for an Arduino shield. There is also an alternate patch PS2 keyboard library for European/French(?) keyboard localization.
Hajos Kontrapunkte wrote about his experience building the keyer.
Stewart, VA3PID, wrote an article about the keyer in the Scarborough Amateur Radio Club newsletter, Wavelength.
Owen, VK1OD, has contributed code and chronicled his Arduino project using this code.
Gerd, DD4DA, maintains a port of the keyer code for the AVR Studio 6 IDE. Gerd has provided code tips, bug fixes, ideas, and feedback
Hamshop.cz offers an ATMega328 based keyer kit with the Arduino bootloader that runs this code.
Chris, K4FH, provided testing, ideas, code, and feedback
Chis, W0ANM, provided testing and feedback
Marcin, SP5IOU, provided code, testing, ideas, and feedback
Peter, NI6E, helped identify bugs and test features. Here’s his discrete component keyer on a breadboard: 
Ryan, KC2ZWM, contributed code.
RemoteQTH offers the Open Interface which runs this code.
Jim, W2XO, provided code.
Bill, W9BEL, provided testing.
Vincenzo, IZ0RUS, provided bug fixes.
Rob, W7FJ, provided bug fixes.
Bill, W9BEL, provided testing, code, and bug fixes.
Giorgio, IZ2XBZ, contributed code and translations
Tim, KF4BZT, contributed ideas and testing and wrote this great article.
Dave, KD7SI, provided a documentation fix.
Hjalmar, OZ1JHM provided OPTION_DISPLAY_NON_ENGLISH_EXTENSIONS code and documented his keyer.
Sverre, LA3ZA, provided additional OPTION_DISPLAY_NON_ENGLISH_EXTENSIONS code work and has documented it here.
If you contributed and I’ve failed to list you above, please email me!
I would like to give special thanks to the staff of an unnamed popular contest logging program for refusing to provide any help in implementing a certain feature and prompting me to create a better technical solution with others who were willing to help.