Tock OS
A secure embedded operating system for microcontrollers
...Written in Rust, it uses a novel kernel architecture where the OS runs a minimal trusted core and all userland code, including device drivers, is sandboxed and isolated. Tock is ideal for IoT devices, wearables, and embedded research projects where reliability and safety are critical. Its capability-based security model and preemptive multitasking allow developers to safely run multiple applications on constrained devices with confidence in memory and fault isolation.