IBM products have undergone numerous evolutions and name changes over the years. In the following summary, the latest series is at the top of each list:
MAINFRAMES
"Z" BRANDS
IBM Z (renaming of System z)
System z (renaming of zSeries)
eServer zSeries (evolved from System/390)
System/390 (followed System 370)
System/370 (followed System 360)
System/360 (original system)
x86-BASED SERVERS
"X" BRANDS (Acquired by Lenovo in 2014)
System x (renaming of xSeries)
eServer xSeries (renaming of Netfinity)
Netfinity (renaming of PC Server)
PC Server (original system)
MIDRANGE BUSINESS SYSTEMS
"I" BRANDS
Power Systems (System i and p merged)
System i (renaming of iSeries)
i5 (evolution of iSeries)
eServer iSeries (renaming of AS/400)
AS/400 (System/38 evolution of
and support for System/36)
System/38 (original system)
System/36 (original system)
SCIENTIFIC & TECHNICAL WORKSTATIONS
"P" BRANDS
Power Systems (System i and p merged)
System p (renaming of pSeries)
p5 (evolved from pSeries)
eServer pSeries (renaming of RS/6000)
RS/6000 (original system)