Zephyr is a small, scalable, real-time operating system (RTOS) optimized for resource-constrained devices, across multiple architectures. Hosted by the Linux Foundation (see [1]), the project is an open-source collaborative effort with the goal of building a best-in-class RTOS. The Zephyr OS has been gaining traction over the past years in embedded computing and today, new microcontrollers and development boards proudly sport Zephyr support. Time to take a closer look.