OS/400 V3

OS/400 (now known as IBM i, previously i5/OS) is the operating system of the AS/400 (now Power Systems, previously System i) series of minicomputers by IBM. It is the replacement for CPF for the System/38 and SSP for the System/36. In addition to a consistent programming environment and a user-friendly interface, it features advanced features not seen in other platforms such as tagged memory, single-level storage, is exclusively written in managed languages.