@LaChasseuse
What can I say.. Lots.
* Raspberry PI (#PiPico', freely documented and with open source toolchains)
* Expressif (#esp32, ESP-IDF is quite open, and there are other fully open source toolchains. Documented by everyone, everwhere.. :-) )
* #WCH, makers of the infamous WCH-CHV 1cent 32bit risc-v mcu are growing, and their ecosystem seems to be developing nicely. Mostly in China but a lot of that ends up getting translated.
* #stmicro; mostly propitiatory tools, but also open source alternatives and a very healthy ecosystem in industrial circles.
* Others that I am forgetting about, the #8050 is still popular, for instance.
* And, weirdly; #Arduino (forked). There are huge chunks of their ecosystem that are already fully open source and qualcomm cannot touch.