The IBM AS/400 (Application System/400), introduced in 1988, is a highly secure, scalable midrange computer system known for its exceptional reliability, integrated DB2 database, and “single-level storage” architecture. Renamed through various iterations (eSeries, iSeries, System i) and now part of IBM Power Systems running IBM i, it remains in use for heavy-duty business, finance, and logistics, supporting legacy applications while allowing for modern web-based interfaces.
