
Emulino
Emulino is an emulator for the Arduino platform by Greg Hewgill, originally found on emulino: arduino cpu emulator. With it, you can build ("Verify") a .pde sketch in Arduino IDE which uses serial port for communication to say a .hex file, and then you can invoke the emulino executable with the .hex file as an argument, and get a local simulation of how an Arduino would behave; useful for debugging without wasting burn cycles on the Arduino's AVR chip.