MQX (Message Queue eXecutive) is a real-time operating system (RTOS) developed by Precise Software Technologies, Inc., and currently sold by Synopsys, Embedded Access, Inc., and NXP Semiconductors. Like most RTOSs, MQX includes a multitasking kernel with pre-emptive scheduling and fast interrupt response, extensive inter-process communication and synchronization facilities, and a file system. Its configurable size conserves computer memory space using a minimum of 6 KB of read-only memory (ROM), including its kernel, interrupts, semaphores, queues, and a memory manager.