The Open On-Chip Debugger (OpenOCD) is a free software aiming to provide debugging, in-system programming and boundary-scan testing. To be used within STM32CubeIDE, STMicroelectronics modified OpenOCD ...
Atmel SAM (ARM core) can be programmed using BOSSA; the equivalent of programming an Atmel AVR using avrdude. On the Arduino Zero, the "native USB" port connects directly to the SAMD21 MCU (PA24,25; ...