This is the file system used by the real-time operating systems QNX 4 and QNX 6 (the latter is also called QNX RTP). Further information is available at <http://www.qnx.com/>. Say Y if you intend to mount QNX hard disks or floppies. To compile this file system support as a module, choose M here: the module will be called qnx4. If you don't know whether you need it, then you don't need it: answer N.