A New Generation’s Chance to Shape the Future: Building the Next Great Java IDE in Open Source

A New Generation’s Chance to Shape the Future: Building the Next Great Java IDE in Open Source

The Eclipse IDE has been a key platform for Java developers and a pillar of the open source community for over two decades. It has helped countless developers build applications, from enterprise software to experimental projects, supporting Java’s ecosystem growth. But like all technology, it must evolve to stay relevant. Enter “Initiative 31”: a bold step toward reimagining what an IDE can be in the 21st century.

In 2025, Eclipse IDE begins an ambitious modernisation journey. Java developers have a unique opportunity to help shape the future of this essential tool. Whether you are an experienced developer or new to the ecosystem, Initiative 31 aims to make Eclipse an OS-agnostic IDE. The primary goal is to reduce maintenance costs across operating systems while ensuring a future-proof solution for developers worldwide.

This article explores the initiative’s technical details, the SWT modernisation process, and how you can contribute to this evolution.

The Eclipse IDE and the Rich Client Platform: Two Sides of the Same Coin

Before exploring Initiative 31, it is important to distinguish between the Eclipse Platform and the Eclipse IDE.

The Eclipse Platform is a set of frameworks and tools designed for both IDEs and rich client applications (RCP), developed mostly in Java. With core services like SWT (Standard Widget Toolkit), JFace, and Equinox, it supports the development of desktop applications beyond traditional IDEs. This versatility has made it valuable in many industries like automotive, space, healthcare systems, avionics, transportation or embedded systems, where reliable and customizable desktop applications are essential. Eclipse remains strong in sectors needing robust and adaptable tools.

Despite its industrial use, the Java development community has gradually moved away from Eclipse as an IDE. Many developers now prefer commercial IDEs or single-vendor open source solutions. These alternatives are often polished and user-friendly but come with trade-offs. Proprietary or single-vendor tools may offer convenience and streamlined workflows but are tied to specific ecosystems, limiting flexibility. In contrast, Eclipse and its platform provide transparency, community-driven development, and adaptability, ensuring long-term sustainability in a changing software landscape.

The Eclipse IDE is an application built with the Eclipse platform, and it is used primarily for Java development. It includes a code editor, debugger, and integration tools, but stands out for its extensibility. With LSP (Language Server Protocol) support, Eclipse IDE can extend beyond Java to other programming languages. This flexibility demonstrates how the Eclipse Platform remains a strong foundation for development environments and desktop tools.

The Birth of Initiative 31: A Bold Vision for Modernisation

Initiative 31 was launched in 2024 with a clear goal: modernising the Eclipse IDE by exploring three technologies to replace or enhance SWT (Standard Widget Toolkit). SWT is the graphical user interface (GUI) toolkit that underpins the Eclipse IDE. It provides a native look and feel by using the operating system’s widgets. This allows Eclipse to integrate seamlessly across platforms while offering better performance than other GUI toolkits. However, maintaining SWT across multiple operating systems has become complex, increasing the need for modernisation. Initiative 31 aims to create an OS-agnostic version, reducing maintenance complexity and costs while improving adaptability and scalability, making sure it is compatible with the existing API

The initiative is led by Heiko Klare, Technical Lead of the project at Vector Informatik, a key member of the Eclipse IDE Working Group. His leadership has been crucial in evaluating new technologies and making key decisions for Eclipse’s future. Under his guidance, the team has focused on assessing various options to modernise SWT.

At the outset, the project focused on evaluating three technologies:

• Skia – A modern 2D graphics library known for its smooth rendering and performance, particularly favored for cross-platform solutions like Flutter.
• Swing – A classic toolkit that had served Eclipse for years but was in need of an update to stay relevant.
• GTK4 – A cross-platform GUI toolkit, particularly suited for Linux environments, but offering potential for broader OS compatibility.

The name “Initiative 31” reflected the plan: test these three technologies throughout 2024 and narrow down the options. The vision was to choose one to lead the future of Eclipse’s graphical user interface (GUI). However, as the project progressed, it became clear that Skia and GTK4 were the most viable options.

The 2025 Reality: Focus on Skia

By 2025, Initiative 31 has shifted its focus. Skia has emerged as the primary choice for modernising Eclipse IDE’s user interface. Skia has become the leading option due to its modern graphics capabilities, cross-platform scalability, and performance benefits. It offers a smoother, more responsive UI.

Given that GTK3 will no longer be supported on Linux starting in 2025, the Eclipse Platform must support GTK4 moving forward, regardless of which option ultimately becomes the primary solution in the Initiative 31 project. Anyway, as always, in the spirit of open source, the future direction of Eclipse IDE will depend on the contributions and decisions of the community.

Revamping the Core: SWT Modernisation Roadmap

The roadmap for Eclipse IDE’s modernisation started with three mature and stable implementations of SWT. In 2024, the team began prototyping these three technologies, and as we move into 2025, it’s clear that the focus has shifted primarily to Skia. The team is now in the realization phase for Skia, with the ambition to create an OS-agnostic implementation. For the time being, this means there will be four implementations: the existing native ones for Linux, Windows, and Mac OS, alongside the new OS-agnostic solution. The ultimate goal is to eventually consolidate all these implementations into a single one, rendering the native versions obsolete:

However, when this happens depends on the community right now… This is where the opportunity to contribute becomes most exciting: you could be part of making this vision a reality, starting now!

Opportunities for Incremental Process with Skia

One key advantage of the Skia approach in this context is its ability to be integrated incrementally into the Eclipse IDE. Unlike traditional “big bang” approaches, where everything changes at once, Skia’s architecture supports gradual adoption of new rendering techniques and widgets. This allows Eclipse IDE to modernise without disrupting workflows or causing compatibility issues for existing users.

Skia’s integration is designed to be non-disruptive, enabling a smooth transition. This incremental approach makes it a strong choice for modernising the Eclipse UI.

Integrating the Ability to Exchange Renderer for Rendering Tasks

One key feature of Skia is its ability to swap out the renderer used by Eclipse. This allows Skia to handle rendering while maintaining native rendering for other tasks. This flexibility lets developers gradually transition to Skia’s rendering capabilities without rewriting the entire UI. It is especially useful for performance-critical or custom-drawn content, such as GEF diagrams, where Skia’s rendering performance provides a clear advantage.

Incremental Replacement of Native Widgets with Custom-Drawn Widgets

Skia’s modular approach allows for the gradual replacement of native widgets with custom-drawn versions. While this may reduce performance when using native custom rendering (e.g., Graphics Context or GC), it enables a smooth transition away from legacy widgets. This avoids a “big bang” migration, allowing Eclipse IDE to evolve one widget at a time without disrupting users.

However, replacing native widgets with custom-drawn ones can create a lock-in effect. This makes it harder to maintain a mix of native and custom widgets in complex UI layouts. Integration can become challenging, especially when combining different rendering methods.

Despite these challenges, the incremental approach with Skia remains a viable path forward. It enables Eclipse to modernise gradually while minimizing disruption. This allows for steady improvements in user experience and performance without the risks of a sudden, large-scale transition.

The March 2025 Eclipse IDE Release: Performance Improvements and Community Contributions

The March 2025 release of Eclipse IDE is released, marking a significant milestone in the platform’s evolution. Alongside Initiative 31, Eclipse IDE has seen major improvements over the past two years, particularly in performance. Performance issues have long discouraged some users, but recent optimization efforts have led to noticeable gains in speed and responsiveness.

The Eclipse community has continued modernising the platform, with contributors in 2023 and 2024 playing a key role in these improvements. The March 2025 release reflects these efforts, introducing optimizations and new features.

This version is the result of years of work, with the number of contributors reaching 271: a notable increase from the previous average of around 200. This growth in contributions highlights stronger community engagement, reflected in the range of enhancements in this release.

New Features and Enhancements in the March 2025 Release

Some of the key highlights of the March 2025 release include:

• Enhanced Light Theme – A new, lightweight tab design and a flat look improve the overall user experience while maintaining familiar functionality.
• Edge as Default Browser – Microsoft Edge replaces Internet Explorer, offering better integration and up-to-date web capabilities.
• Improved Search Filter – Updates to the Import/Export and Show View features improve how category names are handled in searches, allowing for more accurate results.
• Enhanced Code Folding – Now supports control statements, improving navigation in large codebases.
• Custom Formatters for Java – More flexibility in formatting Java primitives and arrays.
• Stack Traces in Variables View – Displays exception stack traces directly in the Variables view, simplifying debugging.
• Quick Fixes and Cleanups – Updated for Java 21 and beyond, providing automatic fixes for common issues.
• Supports Java 23 – Full compatibility with the latest Java version, ensuring access to new features and APIs.

The March 2025 release reflects the ongoing progress of Eclipse IDE, incorporating contributions from the open source community. As the Eclipse platform continues to evolve, this update is part of the broader effort to modernise the IDE while maintaining its flexibility.

And AI? GitHub Copilot in Eclipse Marketplace

Concurrently with the March 2025 release, GitHub Copilot, the commercially licensed extension, is now available in the Eclipse Marketplace. This tool has been requested by the community and is now offered as an extension for developers seeking AI-powered code suggestions.

A New Chapter for Eclipse IDE

Initiative 31 marks a turning point for Eclipse IDE, giving developers a chance to shape the future of Java tools. By modernising the platform, Eclipse aims to stay at the forefront of the open source ecosystem. This is an opportunity for Java developers to contribute to a tool that has influenced software development for two decades.

The path ahead presents challenges, but with community effort, Eclipse IDE will continue to evolve. It will remain a key tool for Java developers worldwide.

And beyond… Building a Fully Open Source Ecosystem: Jakarta EE, Adoptium, and MicroProfile

The future of Java development depends on an open source ecosystem that goes beyond simply hosting code on platforms like GitHub. It requires a thriving community that drives real change. Tools, frameworks, and runtimes like Jakarta EE, Adoptium, and MicroProfile form the foundation of this ecosystem. The goal is a fully open, collaborative stack—from development environments to cloud-native frameworks—ensuring transparency, flexibility, and inclusivity.

Jakarta EE brings enterprise-grade solutions to the cloud, while MicroProfile enhances it with microservices-optimized capabilities. Adoptium keeps Java runtimes high-performance and open, meeting the needs of developers worldwide. This vision extends beyond code; it fosters a global ecosystem shaped by collective efforts. Open source is more than a model—it is a movement essential for solving today’s complex challenges. By adopting these tools and contributing to their growth, we help build a more sustainable, flexible, and impactful future for technology and society.

A Call to Action: How Java Developers Can Contribute

While the technical roadmap is promising, none of this will be possible without the support and contributions of the Java development community. Whether you’re an experienced contributor or someone looking to get involved for the first time, Initiative 31 offers a multitude of ways to make an impact.

• Code Contributions: If you’re familiar with Java development and have experience working with SWT, Skia, or GTK4, this is a perfect opportunity to contribute your expertise to the project.
• Bug Fixes and Feature Requests: Every developer can contribute by reporting bugs, submitting feature requests, and testing new features.
• Documentation: With such a large and complex project, clear documentation is critical. You can contribute by writing tutorials and guides or improving existing resources for new users.
• Application Compatibility Testing: Developers who maintain RCP-based applications are encouraged to test compatibility as the project evolves. This ensures a smooth transition and helps identify potential issues early. It’s also an opportunity to explore a possible path toward a new generation of tools without having to rewrite everything from scratch.

The source code is available on GitHub at https://github.com/swt-initiative31. The technical team holds weekly meetings, and the chat room is open to everyone. Feel free to join, share your ideas, and contribute your thoughts to the project. Your input can help shape the future of Eclipse IDE.

If you’re new to Eclipse projects, you are invited to start with the entry point for new contributors at https://github.com/eclipse-ide. This space is dedicated to answering your questions and helping you get started. Even better, the Eclipse IDE Working Group provides “Community Mentors”: experienced contributors ready to guide you through your first steps in the project.

Looking forward to seeing you there!