(1) (Virtual Memory System) The operating system for Digital Equipment's VAX series (Digital was acquired by Compaq and then HP). VMS was introduced in 1977 for the VAX 11/780 computer. Using virtual memory, as was its namesake, VMS was a sophisticated multiuser, multitasking operating system for that era, which could run on any VAX from the MicroVAX to the largest model. See OpenVMS.
(2) (Voice Messaging System) See voicemail.
(3) (Video Management Software) See network camera.