OpenVMS (Open Virtual Memory System[2]), early versions known as VAX-11/VMS, VAX/VMS or (informally) VMS, is an operating system that runs on VAX, Alpha and Itanium-based families of computers, from 1 MHz single core systems to high-end clustered servers.
Contrary to what its name may suggest today, OpenVMS is not open source software. The term "open-source software" came into being after DEC re-branded VMS as OpenVMS. Open being the standards it meets that are approved in an "open" process. The source listings are available for purchase.
OpenVMS commercialized many features that are now considered standard requirements for any high-end server operating system. These include:
- Integrated computer networking (originally DECnet and later, TCP/IP)
- Symmetrical, asymmetrical, and NUMA multiprocessing, including clustering
- A distributed file system (Files-11)
- Integrated database features such as RMS and layered databases including Rdb
- Support for multiple computer programming languages
- A standardized interoperability mechanism for calls between different programming languages
- An extensible shell command language (DIGITAL Command Language)
- Hardware partitioning of multiprocessors
- High level of security
The OpenVMS operating documentation for various recent releases and for various core OpenVMS layered products is available online at the HP website http://www.hp.com/go/openvms/doc/.
Software Product Description (SPD) documents for many OpenVMS-related products (and for OpenVMS itself) are available at http://h18000.www1.hp.com/info/spd/. SPDs are introductory and legal descriptions of various products, listing the various supported capabilities and product features.
The OpenVMS Frequently Asked Questions (FAQ) contains information and pointers associated with OpenVMS, and is available in various formats at http://www.hoffmanlabs.org/vmsfaq/.
http://en.wikipedia.org/wiki/OpenVMS
As of 2014 VMS Software Inc. maintains and developers OpenVMS. http://vmssoftware.com
