The venerable VMS operating system from Digital Equipment Corp. just turned 30 years old. And hardly anyone noticed.

Nevertheless, in an industry in which change is a constant, VMS has few peers in its age bracket. The hoary software of the IBM mainframe also is more than 30 years old, but that's mainly because it's embedded in a kind of castle that won't fall.

VMS never had a castle. It succeeded at first as the prime operating system of the DEC VAX minicomputer. As Data General, IBM, Wang, and others moved into minis, DEC stayed ahead with its VAX architecture powered by VMS. VMS could run a VAX efficiently; for that matter, it could run whole clumps of VAXes, known as VAXclusters.

As VAX crumbled, VMS moved on. It powered the Alpha line of servers brought out first by DEC, then Compaq. When Compaq was bought by Hewlett-Packard, VMS--now known as OpenVMS--moved on again, this time to Intel Itanium architecture servers.

VMS was designed by Dave Cutler when he was one of the top programmers at DEC. Cutler would move on also, putting his development talents to work at Microsoft, where his experience led to leadership of the Windows NT project. NT's security gains over earlier forms of Windows flowed directly from his VMS experience.

VMS was designed to be secure from the ground up, not as an afterthought, and it had multiple barriers for would-be intruders. It would check the role of someone giving it commands to see whether that person was authorized to do what he was trying to do. If your password was X, and an intruder starting trying to guess passwords using L, M, N, etc., by the time he got to X, VMS would have spotted the pattern and locked his account, even when he got to the right letter.

LOYAL CUSTOMERS

Gareth Williams, associate director of the Smithsonian Astrophysical Observatory Minor Planet Center since 1990, has been tracking the 400,000 orbits of known asteroids and comets in the solar system using a cluster of 12 VAXes, from offices on the Harvard University campus. The Deutsche Börse stock exchange in Frankfurt runs on VMS. The Australian Stock Exchange runs on it. The train system in Ireland, Irish Rail, runs on it, as does the Amsterdam police department. The U.S. Postal Service runs its mail sorters on OpenVMS, and Amazon.com uses it to ship 112,000 packages a day. It has "a very loyal installed base of customers," says Ann McQuaid, general manager of OpenVMS at HP, who shows no signs of wanting to give it up.

After 30 years, can this operating system go on forever? When Compaq decided to kill the Alpha chip, "that did not sit too well around here," says Williams, who's still tracking asteroids on his Alpha servers. HP says it's willing to continue to support OpenVMS as part of its Itanium server lines. But Williams doesn't know when he'll be able to migrate to Itanium, and he isn't sure if HP's commitment is concrete enough to warrant the conversion.

So he's stuck with an old dilemma. "We always said we would move away from VMS when something better came along," he says. "There isn't anything better."