I statically compile the loader. On BSD at least, no 3rd party libs are needed. Then all I need is avr-gcc. I can do everything from the command line. No closed source tools. No requisite graphics layer (e.g., Windows OS). No large interpreters (Python, etc.).
https://raw.githubusercontent.com/PaulStoffregen/teensy_load...
Can anyone recommend other boards where everything can be done like this, i.e., without needing closed sorce tools, graphics layer, or installation of interpreters and scripting libraries?