[carapace]

"There are dozens of us!"

Yep. You can even get a very nice dev system based on it that's commercially supported: https://astrobe.com/

> Astrobe is a complete integrated embedded software rapid development system running on Windows. It includes a multi-file, fully featured, syntax-aware programmer's editor, native code compiler, linker and builder, program uploader and a serial terminal. Use it to develop reliable software to run on the powerful 32-bit ARM Cortex-M3, Cortex-M4 and Cortex-M7 families of microcontrollers.

You can try out the original Oberon OS workstation in your browser here: https://schierlm.github.io/OberonEmulator/ thanks to a JS emulator for the RISC chip!