Wikipedia
MQX RTOS is a real-time operating system developed by Precise Software Technologies Inc., and currently sold by Synopsys, Embedded Access Inc, and Freescale. MQX is an abbreviation standing for Message Queue eXecutive.
Like most real-time operating systems, MQX RTOS 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 memory space taking as little as 6 KB of ROM, including its kernel, interrupts, semaphores, queues and a memory manager.
MQX RTOS includes a TCP/IP stack (RTCS), embedded MS-DOS file system (MFS), USB Host/Device Stack, as well as Design, Task-Aware debugging (TAD), Remote debugging and performance analysis tools.
MQX RTOS is generally used in embedded systems. MQX development is done on a "host" machine running Unix or Windows, cross-compiling target software to run on various "target" CPU architectures.
MQX RTOS has been ported to a number of platforms and now runs on practically any modern CPU that is used in the embedded market. This includes Kinetis, ColdFire, PowerPC, ARC, ARM, StrongARM, xScale CPUs.
All new Kinetis (ARM - CortexM4) and ColdFire devices are to be enabled with complimentary Freescale MQX RTOS. Freescale plans to expand the availability of this complimentary integrated enablement software to include many embedded processors in its broad portfolio.