With System V, AT&T introduced three new forms of IPC facilities (message queues, semaphores, and shared memory). While the POSIX committee has not yet completed its standardization of these facilities, most implementations do support these. In addition, Berkeley (BSD) uses sockets as its primary form of IPC, rather than the System V elements. Linux has the ability to use both forms of IPC (BSD and System V), although we will not discuss sockets until a later chapter.
The Linux implementation of System V IPC was authored by Krishna Balasubramanian, at [email protected].