IBM's midrange computer family, which uses IBM's POWER CPUs. In 2008, IBM merged its System i and System p hardware into the Power Systems brand. It was an easy transition as both System i business computers and System p scientific computers were based on POWER chips, with applications differentiated by operating system. Business applications run under the IBM i operating system, and scientific applications run under AIX (Unix) or Linux. THE BUSINESS SIDE - AS/400 The business side of Power Systems stems from the AS/400 in 1988 for which thousands of applications have been written over the years. Its unique feature was a relational database that came with the OS/400 operating system, and applications from earlier IBM systems either ran intact or with recompilation (see System/38 and System/36). AS/400-> iSeries-> i5-> System i-> Power Systems In 1994, AS/400 models were introduced with the POWER CPUs, and in 2000 IBM renamed the AS/400 the "iSeries." In 2004, the i5 was introduced with the POWER5 CPU and a wide range of models, including systems with 64 CPUs and 2TB of memory. The OS/400 operating system was renamed i5/OS (later IBM i). Subsequent models were branded "System i."