iSeries is IBM’s midrange server line, designed for small agencies and departments in large companies. The product line, formerly called AS/400 still the favorite name among many long time users , was renamed in 2000 with the advent of the V5R1 operating system and 800 line of servers. i5 is the latest hardware evolution of one of IBM’s most widely installed product lines. iSeries servers use IBM’s Power5 microprocessors and are capable of operating five different working approaches at an identical time AIX, Windows, Linux, OS/400, and i5/OS on multiple partitions.
IBM also offers p5 or pSeries servers for big enterprise users who want to run Unix procedures or who need more scalability.