OpenVMS is a computer operating system. The name stands for Open Virtual Memory System. Despite the name, OpenVMS is a closed-source operating system. Digital Equipment Corporation (DEC) produced the operating system and related computers and software, but Hewlett Packard (HP) is the current successor of DEC. Companies and organizations use OpenVMS for a variety of purposes, including hosting mail servers and providing network services. The OS is useful for database and batch processing functions and timekeeping. Though the operating system works on specialized VAX and Alpha computers, programmers can use specialized software to run it on Windows servers.