Opening up the Mainframe

Zowe is poised to break new ground for IBM Z

By Keelia Estrada Moeller


Zowe, a new open-source framework, enables development and operations teams to securely manage, control, script and develop on the mainframe like any other cloud platform.

The project was first announced Aug. 14 during SHARE in St. Louis by executives from IBM, CA Technologies, Rocket Software and the Open Mainframe Project. As the first open-source project for z/OS, Zowe is poised to break new ground for IBM Z clients.

“Open source redefines industries across the board. We’ve seen it solve problems and lead to innovative solutions,” says John Mertic, director of program management for The Linux Foundation and director for the Open Mainframe Project. “We’re excited to see what Zowe and open source will do for the mainframe industry.” To learn more about what open source is and why it’s beneficial, see “What Is Open Source and How Does It Apply to IBM Z?”

Zowe’s Origins
Zowe first emerged as a way to facilitate the onboarding of the next generation of mainframers—making the IBM Z platform more open and accessible. “The whole idea for the project came from the mainframe community. We all love IBM Z, but we’ve also seen other platforms accelerate in growth because they’ve embraced open source,” explains Andy Youniss, president and CEO, Rocket Software. “More and more mainframe users and mainframe clients were waiting for the day IBM Z would finally be open, too.”

In a way, going into open source with Zowe means bringing the mainframe back to its roots. Open source traces back to SHARE in the 1950s, where mainframe programmers came together to share source code over tape and printouts. They worked together in an effort to improve everyone’s source code. “The mainframe community has been doing open source before open source was even a name,” Mertic says.

The name “Zowe” (pronounced zō-wē) also has a meaningful message behind it. “We had this desire to have something catchy and easy to say, and we liked how ‘Zowe’ sounded. That’s when we ended up thinking about the spelling,” says Greg Lotko, mainframe general manager, CA Technologies. Eventually, everyone agreed to spell it Z-O-W-E. “The ‘Z’ brings in IBM Z, the ‘O’ alludes to open source and the ‘WE’ brings in a common theme of inclusivity,” adds Barry Baker, vice president, IBM Z Software, IBM.

Seeing the Mainframe Light
The contributors that brought Zowe to fruition already understood the value behind the IBM Z platform. Unfortunately, they also knew that not everyone sees how crucial the mainframe is to everyday operations. “We have this great platform that does so much heavy lifting for the world. It’s extremely secure and it processes things faster than anything else,” says Lotko. “We’ve all been searching for ways to have others see the light and understand what it is we know.”

The founders decided the best way to help others see this mainframe “light” was to listen to the community and opt for open source. Zowe is designed to open the platform, enable the community and attract new people to the mainframe. For this to happen, the platform had to appear familiar and open.

“We all quickly concluded that, if we’re going to look familiar to someone new, there’s a set of foundational elements the platform should have. It has to be common, and it can—and should—be accessible to anybody,” says Baker.

As a development methodology that encourages collaboration, transparency and inclusivity, open source was the best way to make the mainframe accessible to a larger network of people. Because open source provides transparency, it can enable organizations to leverage the creativity of a global ecosystem of people. It also provides the freedom to inspect, modify, enhance, contribute or reuse code.

“We have this great platform that does so much heavy lifting for the world. ... We've all been searching for ways to have others see the light and understand what it is we know.”

Greg Lotko // Mainframe general manager, CA Technologies

Collaboration and the Open Mainframe Project
Collaboration is fundamental for open source, but it was also pivotal during the development of Zowe. IBM, CA Technologies, Rocket Software and the Open Mainframe Project each brought their unique perspectives to the table to make Zowe the best it could be. “We got together and, based on our companies’ histories, we knew we each had our own user communities. We had extremely collaborative sessions because we all brought our own perspectives, and that’s when the magic really happened,” says Youniss.

IBM’s initial contribution to Zowe was an extensible z/OS framework that provides REST-based services or APIs, allowing users to utilize existing technology, tools, languages and modern workflows with z/OS.

More recently, IBM contributed z/OS Explorer Core, giving developers a set of discoverable foundational services that can be used across all aspects of Zowe.

Rocket Software provided an extensible Web UI and desktop motif, an app integration capability and a 3270 emulator.

CA Technologies provided both the Zowe command line interface and the API mediation layer, simplifying consumption of Zowe RESTful API services.

The Open Mainframe Project—a foundation hosted by The Linux Foundation—provided a vendor-neutral home for open source on the mainframe and was key in making Zowe successful. The Open Mainframe Project has worked on several open-source projects in the past as well, providing a broad range of expertise. It’s hosted an internship program where students worked on open-source projects, assisted existing open-source projects that needed additional support and more.

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Gaining Momentum
Zowe is one of the more substantial projects the Open Mainframe Project has supported. It has the potential to unleash open-source efforts within the mainframe community, and so far, that’s exactly what it has done. Zowe has also helped jumpstart other open-source projects that were in the early stages of launching.

Zowe has picked up momentum within the mainframe community since its inception. A May 2019 statistics report showed that has had over 3,000 downloads since the 2018 announcement at SHARE. The Zowe community has also grown to over 950 active Slack users, with over 50 active contributors. All of these numbers are expected to continue growing.

Zowe’s Future
Inclusivity defines Zowe. This is a huge step forward for the mainframe ecosystem, but the true test lies in what kind of transformation Zowe will bring. “We’re looking forward to seeing what Zowe becomes and how it will transform the community over time,” says Mertic.

Where the project goes is up to the community. The project’s founders are excited about its prospects. “Zowe is about empowering the community. We could have this go into places where we would never have thought of,” says Youniss. “We’ll all be here for guidance, but the collective mainframe community will bring Zowe where it ultimately needs to go.”

When it comes to Zowe and open source in general, much work remains to be done. But if Zowe continues to spread through the mainframe community, it will enable more engaging ecosystems to grow, opening up the platform to future generations and helping others see its value. Zowe’s founders look forward to seeing more contributors and companies collaborate on Zowe.

Get involved with Zowe, learn about the contribution guidelines, look at the source code or download and try different components of Zowe at

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