RIOT

RIOT is an open-source operating system designed for Internet of Things (IoT) devices with constrained resources. It provides a POSIX-like API, networking stacks (including IPv6, 6LoWPAN), and real-time capabilities suitable for embedded systems. The project focuses on portability, energy efficiency, and a small footprint to run on microcontrollers. RIOT's ecosystem includes tools for development, testing, and debugging firmware across many hardware platforms. It is widely used in research and security testing for analyzing device behavior and vulnerabilities in IoT deployments.