OpenVMS
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers. During the 1990s and 2000s, there were approximately half a million VMS systems in operation worldwide.
OpenVMS V7.3-1 running the CDE-based DECwindows "New Desktop" GUI | |
| Developer | VMS Software Inc (VSI) (previously Digital Equipment Corporation, Compaq, Hewlett-Packard) |
|---|---|
| Written in | Primarily C, BLISS, VAX MACRO, DCL. Other languages also used. |
| Working state | Current |
| Source model | Closed-source with open-source components. Formerly source available |
| Initial release | Announced: October 25, 1977 V1.0 / August 1978 |
| Latest release | V9.2-2 / January 25, 2024 |
| Marketing target | Servers (historically Minicomputers, Workstations) |
| Available in | English, Japanese. Historical support for Chinese (both Traditional and Simplified characters), Korean, Thai. |
| Update method | Concurrent upgrades, rolling upgrades |
| Package manager | PCSI and VMSINSTAL |
| Platforms | VAX, Alpha, Itanium, x86-64 |
| Kernel type | Monolithic kernel with loadable modules |
| Influenced | VAXELN, MICA, Windows NT |
| Influenced by | RSX-11M |
| Default user interface | DCL CLI and DECwindows GUI |
| License | Proprietary |
| Official website | vmssoftware |
It was first announced by Digital Equipment Corporation (DEC) as VAX/VMS (Virtual Address eXtension/Virtual Memory System) alongside the VAX-11/780 minicomputer in 1977. OpenVMS has subsequently been ported to run on DEC Alpha systems, the Itanium-based HPE Integrity Servers, and select x86-64 hardware and hypervisors. Since 2014, OpenVMS is developed and supported by VMS Software Inc. (VSI). OpenVMS offers high availability through clustering—the ability to distribute the system over multiple physical machines. This allows clustered applications and data to remain continuously available while operating system software and hardware maintenance and upgrades are performed, or if part of the cluster is destroyed. VMS cluster uptimes of 17 years have been reported.