QNX RTOS ranked second among general-purpose, hard real-time operating systems, based on data from a recent survey conducted by CMP, Inc. (Embedded Systems Programming, June, 2005, pp. 36-40). The CMP survey measured RTOS market share through questions posed to a large group of embedded developers, including attendees of Embedded Systems Conference, and subscribers to EE Times and Embedded Systems Programming.A key survey question asked developers which operating system they currently use. As can be seen in the chart, Wind River's VxWorks(R) topped the results with an 18.4% response. The next highest-ranking hard real-time OS was QNX with a 6.1% response, followed by ThreadX with a total of 5.4%, with combined results from Express Logic and Green Hills Software sales channels. Other operating systems that do not handle hard real-time requirements, such as Red Hat Linux, Microsoft Windows CE and NT Embedded earned between 7 and 13%. TI's DSP/BIOS received 7%, but it is only available for certain TI DSPs.
Looking to the future, a related question asked developers which OS they were likely or highly likely to use in the next 12 months. Here ThreadX scored 11.0%, and ranked second only to VxWorks at 20.4% among hard real-time, general-purpose RTOSes.