6ardamu

Its main competitor these days seems to be RIOT: https://www.riot-os.org/

There are several mentions that Peter died from metastatic cancer. This is not entirely accurate. He choose to leave this world using euthanasia as his last tweet shows[0]. Euthanasia is legal in Belgium.

[0] https://twitter.com/hintjens/status/783254242052206592?s=20

IceSL[0] would also qualify to be on that list. [0]: https://icesl.loria.fr/

A notion of subsumption was also studied in the context of QBF solving. https://doi.org/10.1007/978-3-642-24372-1_14