Apache NuttX Apache NuttX is a mature, real-time embedded operating system (RTOS). Get NuttX Apache NuttX NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are Posix and ANSI standards. Additional standard APIs from Unix and other common RTOS