OpenVMS

OpenVMS is a multi-user, multiprocessing operating system with a long history in enterprise computing. Originally developed by Digital Equipment Corporation as VAX/VMS, it was designed for reliability, security, and scalability in mission-critical environments. The system has found enduring use in finance, aerospace, government, and other sectors that require high availability and strong data integrity.

OpenVMS began on the VAX platform in the late 1970s and was renamed OpenVMS after DEC ported it to the Alpha architecture in the 1990s. It has since been ported to additional architectures, including Itanium and x86-64, with development and stewardship transitioning to VMS Software Inc. (VSI) in the 2010s to ensure ongoing maintenance and enhancements.

The operating system provides robust features for enterprise workloads, including the Files-11 data/file system (with ODS-2 and ODS-5 variants), the RMS data management layer, and strong clustering support through OpenVMS Clusters. It includes system management tools, the DCL command language, and optional GUI support via DECwindows; it supports languages such as C, Ada, COBOL, Fortran, and BASIC.

OpenVMS emphasizes high availability, with features such as online backups, rolling upgrades, and fault-tolerant clustering to minimize downtime. It runs on multi-processor servers and scales to large workloads, using middleware, security features, and virtualization options to maintain service continuity in critical environments.

Today, VSI continues OpenVMS development for current architectures, including ongoing porting efforts and modernization while maintaining backward compatibility for long-standing OpenVMS applications and environments.