Zephyr

A scalable, open-source Real-Time Operating System (RTOS) for connected, resource-constrained devices: backed by the Linux Foundation.

Zephyr is a new-generation, highly configurable RTOS, specifically engineered for resource-constrained embedded systems and IoT devices. Hosted by the Linux Foundation and licensed under Apache 2.0, its modular architecture enables a minimal memory footprint (as low as 8K). The platform ensures robust, secure development with features like memory protection and secure boot (MCUboot). It supports a broad ecosystem: over 800 development boards across multiple architectures (e.g., ARM, RISC-V, x86). Deploy Zephyr to build secure, scalable, and connected applications for the modern edge.

https://www.zephyrproject.org