OSEK (Open Systems and the corresponding Interfaces for embedded, Real-time Systems) is an open standard for real-time operating systems (RTOS) used in embedded systems such as automotive or avionics applications. It provides a set of specifications and APIs for developing real-time applications that require predictable behavior, efficiency, and reliability. OSEK supports various hardware platforms and enables the development of reusable and interchangeable software components while ensuring compatibility and interoperability between different systems.