Ah Taos! One of serveral very interesting OSes from late 1980s and early 1990s. Grasshopper, Jaguar, Oberon are a few others from the same era.

Its probably my age and not keeping up with the research, but it feels like there were more diversity and cool things going on in OS reserach and R&D back then.

Though the development of VMs and OSes for IoT and mobile devices is probably a good counterpoint.