(cue-nix) 1. N. A popular Unix-like real-time operating system that has been widely used to develop real-time systems based on PC-like x86 platforms. The latest versions of QNX are wellknown for their ability to run on any standard PC and for their nifty Linux ABI compatibility features, though other processors and platforms are also supported. 2. N. The company that makes the QNX RTOS. Short for QNX Software Systems.