The main responsibility of an operating system is to manage a computer's resources. All activities in the system—scheduling application programs, writing files to disk, sending data across a network, and so on—should function together as seamlessly and transparently as possible.
Some environments call for more rigorous resource management and scheduling than others. Realtime applications, for instance, depend on the OS to handle multiple events and to ensure that the system responds to those events within predictable time limits. The more responsive the OS, the more "time" a realtime application has to meet its deadlines.
The QNX Neutrino RTOS is ideal for embedded realtime applications. It can be scaled to very small sizes and provides multitasking, threads, priority-driven preemptive scheduling, and fast context-switching—all essential ingredients of an embedded realtime system. Moreover, the OS delivers these capabilities with a POSIX-standard API; there's no need to forgo standards in order to achieve a small system.
QNX Neutrino is also remarkably flexible. Developers can easily customize the OS to meet the needs of their applications. From a "bare-bones" configuration of the microkernel with a few small modules to a full-blown network-wide system equipped to serve hundreds of users, you're free to set up your system to use only those resources you require to tackle the job at hand.
QNX Neutrino achieves its unique degree of efficiency, modularity, and simplicity through two fundamental principles: