AS400
Also known as: AS/400, iSeries, System i
The AS400 (Application System/400) was introduced by IBM in 1988 as a midrange business computer. Over the decades it evolved through product names including AS/400, iSeries, and System i, before the hardware line was folded into today's IBM Power Systems running the IBM i operating system. Despite the name changes, the term AS400 persists in business language because many organizations have run mission-critical applications on this platform for 20 to 30 years. The AS400 platform is known for its exceptionally high reliability, integrated database (Db2 for i), and strong security architecture. It is widely used in manufacturing, distribution, healthcare, finance, and government. AS400 and IBM Power Systems are not strictly interchangeable: IBM Power Systems is the current, broader server line (also running AIX and Linux workloads with no AS400 lineage), while AS400 specifically refers to the IBM i heritage. Organizations looking for AS400 support or IBM Power resellers are often searching for partners who can maintain legacy IBM i environments while also planning for modern hardware refresh cycles.