"Sculpt is an open-source general-purpose OS. It combines Genode's microkernel architecture, capability-based security, sandboxed device drivers, and virtual machines in a novel operating system for commodity PC hardware and the PinePhone. Sculpt is used as day-to-day OS by the Genode developers. "
running on seL4, which is arguably one of the great achievements in verified software, it's so conceptually interesting!