Real-Time Executive for Multiprocessor Systems (RTEMS) is an open source fully featured Real Time Operating System (RTOS) that supports a variety of open standard application programming interfaces (API) and interface standards such as POSIX and BSD sockets. It is used in space flight, medical devices, networking and many more embedded systems across a wide range of processor architectures including ARM, PowerPC, Intel, Blackfin, MIPS, Microblaze and more.