This commandline application for the Micronucleus bootloader is written by ihsan Kehribar and Bluebie It's been tested casually on Mac, Windows, and Linux, and aught to work on all three. To make and install, do the regular 'make; sudo make install' on unixes. On windows just 'make' with mingw and do whatever people do with windows exes. Usage on Ubuntu: sudo micronucleus --run name_of_the_file.hex Usage on Mac: micronucleus --run name_of_the_file.hex Usage on Windows micronucleus.exe --run name_of_the_file.hex Raw binary file writing hasn't been tested much yet and is suspected to not work. Every now and then the program fails once it reaches the Writing stage - this is a known bug - but if you simply rerun the micronucleus command immediately, it will succeed the second time usually. Most of the time this issue is not present.