OpenVMS is an operating system developed by Digital Equipment Corporation, initially for the VAX family of computers (then named VMS), later ported to Alpha, x86 and Itanium. The operating system is multi-user and multi-tasking, with integrated clustering and real-time programming support. OpenVMS is targeted for the systems of higher level availability and safety. The OS features a common language environment, which defines the calling conventions and access to the system. In effect, the modules written in different languages may freely call each other, as well as the system services, making OpenVMS truly language-agnostic.