Why is defending the mainframe so difficult? One reason is that many people do not fully understand what is meant by the term “mainframe.” Ubiquitous computing leads many to believe that the mainframe is an amorphous type of computer from the mid-20th century that was made obsolete by laptop computers and mobile technologies. Nothing could be further from the truth. Mainframe computing still plays a vital role in global computing, just as personal computing does.
To be clear, by “mainframe,” our focus is on enterprise class mainframes, specifically IBM Z. While years ago, the term “mainframe” could refer to any number of large computer systems, today, the remaining representative of this class of computers is the IBM Z. In March 1991, Stewart Alsop, one-time editor in chief of InfoWorld said, “I predict that the last mainframe will be unplugged on March 15, 1996.” The perception is that “everyone knows that the mainframe is dead.” Yet, nearly 25 years later, the mainframe is still prevalent in many industry sectors, particularly for government and financial operations.