OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer
DB/2 - in a false derivation from the operating system OS/2 .) Unlike other database vendors, IBM previously produced a platform-specific Db2 product for
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360