This article is based on commentary from Broadcom published in the Arcati Mainframe Yearbook and reporting originally appearing on it.toolbox.com.
The Mainframe Is Not Going Away — But Its Tooling Needs to Evolve
For decades, mainframe developers relied on tools like ISPF green screens and the Eclipse desktop IDE augmented with proprietary plugins. These tools served their purpose well, but the wider software development world has moved on — and mainframe tooling must follow.
Broadcom highlighted this challenge in the Arcati Mainframe Yearbook, pointing to two converging pressures: a generational shift in the developer workforce and a dramatic acceleration in software delivery expectations.
A Workforce Shift and the Rise of Modern IDEs
Experienced mainframe engineers are retiring at a steady pace. The developers stepping in to replace them have grown up with modern toolchains and expect to keep using them. According to data cited from the Stack Overflow Developer Survey, Visual Studio Code’s popularity among developers grew from 34.9% to 50.7%, while Eclipse declined from 18.9% to 14.4% over the same period. Python emerged as the most sought-after scripting language skill.
These preferences are not just cosmetic. Developers who are comfortable in VS Code or browser-based environments will be less productive — and less happy — when forced into legacy toolchains. For enterprises that depend on mainframe talent pipelines, this is a real recruitment and retention risk.
DevOps Velocity Demands Are Reaching the Mainframe
Software delivery expectations have changed fundamentally across the industry. Data cited from 451 Research indicated that 24% of companies release application software daily or hourly. DORA’s State of DevOps report placed 20% of organizations deploying multiple times per day. Continuous deployment is no longer aspirational — it is the baseline expectation.
For the mainframe to remain a viable platform for application development — rather than just a runtime for legacy batch jobs — its development workflows need to match these cadences. That requires modern CI/CD-compatible tooling, scripting via CLIs, and team collaboration capabilities that distributed development teams already take for granted.
Eclipse Che and Che4z: A Browser-Based IDE for Mainframe Developers
Eclipse Che is an open-source, Java-based developer workspace server and browser-based IDE that is container-native. It was architected to deliver a VS Code-like experience from the browser, built on Eclipse Theia. Theia implements the same tooling protocols that underpin VS Code — the Language Server Protocol (LSP), Debug Adapter Protocol, and compatibility with VS Code extensions — making the transition familiar for developers already working in that ecosystem.
The analogy often used is Git: its usability and collaborative design made it the de facto standard for version control across teams of all sizes. Che’s workspace server aims to deliver comparable collaborative benefits, particularly for hybrid IT teams working across mainframe and distributed platforms.
The Che4z subproject, contributed by Broadcom, extends Che specifically for mainframe development. It provides:
- Access to the z/OS file system
- Remote editing and debugging of COBOL programs
- Syntax highlighting, code assist, and real-time syntax validation
- Language Server Protocol support for COBOL (with High-level Assembler planned)
Because Che4z uses LSP, developers can use COBOL with Che, VS Code, or any other LSP-compatible editor such as IntelliJ, VIM, or Emacs — significantly broadening the reach of mainframe language support without requiring a proprietary plugin ecosystem.
Zowe: The Open Source Foundation That Makes It Possible
The Che4z extensions are powered by Zowe, the first open source project based on z/OS. Zowe was founded by Broadcom, IBM, and Rocket Software and enables developers to manage, control, script, and develop on the mainframe using familiar patterns from cloud development — all while maintaining mainframe-native security standards.
While open source is not new to mainframe environments — zLinux has existed for years — Zowe was a significant step in opening access to off-platform toolchains. The Zowe CLI is a key component of the Che4z stack, enabling the kind of scripting and automation that underpins DevOps adoption. CLIs allow developers to automate repetitive tasks, integrate with pipelines, and script complex workflows — capabilities that were difficult or impossible with traditional mainframe tooling.
Code4z: Bringing Mainframe Development Into VS Code
For developers who prefer to stay in their desktop environment rather than a browser-based IDE, Code4z is a free Visual Studio Code plugin that provides access to mainframe datasets and elements directly from VS Code. It allows developers to write and manage mainframe code using the most popular desktop IDE available today, without needing to context-switch into a separate toolchain.
Why Containerized Workspaces Matter for Mainframe Teams
Because Che workspaces are containerized, they carry meaningful operational advantages over traditional desktop IDE setups:
- No local installation: Developers open a container and begin work immediately, with no environment configuration on their local machine.
- Fast onboarding: New team members can be productive in minutes rather than days — a critical advantage when mainframe talent is scarce.
- Reduced maintenance overhead: The heavyweight plugin management required by Eclipse-based setups is eliminated.
- Pair programming support: Che facilitates real-time collaboration between mainframe and distributed developers working on cross-platform applications.
For mainframe leaders under pressure to reduce costs and onboard the next generation quickly, migrating teams from Eclipse-with-customizations to a containerized Che environment represents a concrete opportunity to reduce operating costs and improve developer productivity.
Bridging Mainframe and Cloud: The Hybrid IT Case
For many large enterprises, the mainframe hosts critical systems of record — transaction engines and authoritative data stores — while cloud and mobile applications serve as systems of experience. Cross-platform applications increasingly need to combine the transactional power and data assets of the mainframe with modern user interfaces built on cloud and mobile stacks.
This integration work falls on cloud and mobile developers who are unfamiliar with mainframe tooling. Allowing them to use the editors they already know — VS Code, Che, LSP-compatible IDEs — removes a significant barrier and accelerates delivery. The open source, standards-based approach taken by Che and Zowe is central to making that practical.
Commercial Support for Open Source Mainframe Tools
Enterprises that depend on mainframe infrastructure are understandably cautious about adopting open source tools without a clear support model. Vendors including Broadcom address this by offering commercially supported versions of these open technologies alongside the open source releases.
Broadcom’s CA Brightside product, for example, provides a streamlined installation path, technical and legal support for Zowe core capabilities, and certified integrations with proprietary solutions such as CA Endevor SCM, CA File Master Plus, and CA OPS/MVS. This model allows enterprises to adopt open source tooling at their own pace while maintaining enterprise-grade support coverage.
The Broader Revolution in Mainframe Application Development
The convergence of Che, Che4z, Zowe, and Code4z represents more than a tooling refresh. It signals a fundamental shift in how mainframe development is positioned — away from a siloed, vendor-controlled ecosystem and toward participation in the same open source communities, protocols, and workflows that drive development on every other platform.
Expanded tool choice, greater alignment with off-platform development peers, and DevOps-compatible software delivery cadences are the practical outcomes. For organizations managing hybrid IT estates — where mainframe reliability and cloud agility both matter — this open source foundation is what makes sustainable modernization possible.
The Che4z extensions are open sourced and free to use. Community contributions are welcomed by both the Che and Che4z projects.