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The Value of Open-Source Software on the Mainframe

Mainframes, as we know, are fast, reliable and secure. They can deliver data to users faster than any other platform—particularly, cloud-based systems—and they can ensure that the data is encrypted in transit, while stored and even when in use. The software that runs on these computing behemoths comes from reputable software vendors who ensure their products can’t be hacked, and release updates if any vulnerabilities are found.

On the downside, mainframe software is very expensive to run when you look at the bottom line compared to other platforms available. However, when you compare it against the number of transactions that can be run, for example, then the price doesn’t seem so outrageous. Even so, many people are looking at the idea of open-source software (OSS) as an alternative or as an addition to their usual mainframe software. The question I’d like to examine is whether this is a good idea.

The Pros and Cons of Open Source

When people think of open-source software, they usually picture an enthusiast who has written a piece of code for their own use, which they then share with the rest of the user community. Many mainframers will remember the Update publications from Xephon that contained pieces of code that people had written and shared in just this way. Obviously, anyone using the code would test it in their own environment before going live. But that is quite different from getting packaged OSS code that you just install and run.

Many mainframers and their managers worry that any open-source software that they install may have security flaws in it, and it may take a while for anyone to fix those bugs. They also worry whether anyone will be working on the software to update it in the future. They feel that the whole idea is fraught with risks. Although OSS may at first seem free to the user, there is the cost of training staff to use the new software—and there is the cost of running that extra load on your mainframe.

However, there are several benefits to using OSS. For example, many mainframe sites have gone down the modernization route and are now using cloud computing for some of their work. There are several open-source products that can be used to make cloud computing work better with mainframes.

There are open-source products that can run on mainframes and make the mainframe, with its traditionally arcane way of working known only to the keepers of mainframe lore, available to people who have a great deal of experience on other platforms. I was going to call them modern platforms, but I can remember working on the original IBM PCs back in the early 1980s, so that makes that platform 40 years old. OSS helps fill the skills gap that has been talked about for the past few years as experienced mainframers start to retire.

Open-Source Software Use Cases

OSS can be used to connect mainframes to other platforms, enabling applications to run across platforms as needed by users. OSS can also help users to develop new products quickly and get them to market ahead of their competitors.


So, what open-source software is available for mainframes? First, and probably the best known, is Zowe. Zowe is open-source technology that was announced in 2018 by the Open Mainframe Project as a way for non-mainframers to securely manage, control, script and develop on the mainframe like any other cloud platform. Initial development came from IBM, Broadcom and Rocket Software—three heavyweight software houses for mainframes. One of many advantages for sites using Zowe is that it has the look and feel of software developed off-mainframe, meaning it is easily accessible by people with no mainframe training, empowering them to work productively and successfully on a mainframe.


The Open Mainframe Project also has GenevaERS, which is a single-pass optimization engine for data extraction and transformation on z/OS.


And, of course, there’s Ansible. Using Ansible on a mainframe provides a way to integrate z/OS into an enterprise automation strategy in a consistent way. With Ansible, it’s easy to onboard new systems programmers, DBAs and developers—as well as manage infrastructure and provisioning changes as code.

Using Ansible, users gain simple access to applications and data with secure API creation and integration in minutes. Ansible provides agile enterprise DevOps. For example: cloud-native development with industry-standard open tools. Ansible also provides standardized IT automation and, in fact, it can reduce the need for specialized skills and empower developers.

The Ansible for IBM Z collection contains a powerful set of playbooks and modules that allow users to automate common z/OS tasks. There are also dedicated collections and samples for different IBM products such as IMS and CICS. These are available on Ansible Galaxy. The collections cover basic z/OS tasks and those needed for Db2, CICS and IMS.

DevOps and Git

When it comes to DevOps, mainframers can now use Git as an application development environment, or VS Code, which is a source-code editor made originally by Microsoft for Windows. VS Code is a very popular editor and has built-in Git capabilities. Broadcom’s free Code4z extension pack makes VS Code and similar tools easily available to mainframe developers. With these tools, mainframe applications can be built by people with lots of experience of those two products without much mainframe experience.

To be clear, I’m not saying that all open-source software is great and you should rush out and install it. What I am saying is that there is plenty of excellent open-source software available, and once you determine that it meets your site’s stringent security standards, it’s well worth installing and using because it can make using the mainframe easier for everyone.