The first hypervisors providing full virtualization were the test tool SIMMON and IBM's one-off research CP-40 system, which began production use in January 1967, and became the first version of IBM's CP/CMS operating system. CP-40 ran on a S/360-40 that was modified at the IBM Cambridge Scientific Center to support dynamic address translation, a feature that enabled virtualization. Prior to this time, computer hardware had only been virtualized to the extent to allow multiple user applications to run concurrently, such as in CTSS and IBM M44/44X. With CP-40, the hardware's "supervisor state" was virtualized as well, allowing multiple operating systems to run concurrently in separate virtual machine contexts.