µnix (or munix, if you can't type µ) is an RTOS and HAL, inspired by FreeRTOS, but designed to be used for secure realtime applications. It requires minimal overhead per thread, and offers a wide variety of functions to securely handle data, as much as the platform allows. Source code can be shared easily between platforms with µnix support, with compile-time failures if features are needed but not available.
TODO: More explanation! Why I picked it for the blog, where its docs are, etc.