μT-Kernel is an open source real-time operating system (RTOS) designed for 16- and 8-bit microcontrollers.

[1] The source code is available from the TRON Forum website and GitHub.

[5] An article comparing nine RTOSs in which μT-Kernel was evaluated and given favorable remarks appeared in IEEE publication.

[8] μT-Kernel was developed as a smaller subset of T-Kernel, a full-featured real-time operating system.

For more on its history and the overall philosophy behind the TRON real-time OS family, please see the entry of T-Kernel.