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Middleware Makes so Much Productivity Possible

October 29, 2013

Editor's note: This is first part of a series on this topic.

My first three posts were a look-back, focusing on the things that excited me when I got started in computing on mainframes more than 30 years ago. In this post, I begin a series of descriptions on the important category of software called middleware.

Middleware is big business in the software industry and is estimated to continue to grow in revenue each year into the future. The technology behind middleware is much needed and the notion of a functional layer between the OS and the application is a simple but brilliant idea. Not all middleware fits this precise functional-layer model but that simply is variability that we have come to expect in IT. You have to admit that having software that is written to makes things easier that actually helps you is very cool. Don’t you agree?

Where did the middleware idea come from? Its earliest use as a term has been traced to a report from the 1968 NATO Software Engineering Conference: (see: Today, many programmers assume that middleware was invented along with client-server computing as a toolset to connect distributed components; however, the roots of middleware are clearly in centralized enterprise systems.

Job Entry Subsystem (JES) was an early middleware engine whose productivity shell was Job Control Language (JCL). Without JES and JCL, getting work into a system would have been very challenging and each programmer would have solved the challenge in a different way. This is what happened in mainframe computers before the creation of a job-entry system. For years, I taught JCL to new programmers and operations personnel. Many people thought JCL was difficult but after some education and support they soon realized that it was subtle yet straightforward. Fortunately, they never had to struggle with scheduling and monitoring work before JES and JCL.

JES was a great productivity idea and the proof is its continued use, support and growth. JCL is still in wide use and has not stood still, experiencing important changes and improvements in its content and use.

By the way, here is a good overview of JES from the z/OS concepts manual.


Posted October 29, 2013| Permalink