NetNewsWire Completes Massive Swift Migration After Developer Retirement

NetNewsWire developer Brent Simmons reported on the app’s progress in an official blog post, a year after his retirement. Simmons retired with his last day of work being June 6, 2025, but during that time he continued to focus on developing the open-source RSS reader NetNewsWire. Over the past year, he accumulated 2,188 commits, achieving a large-scale modernization of the codebase.

Simmons recalled, “My hope after retirement was to get a lot of work done on NetNewsWire. A year ago, the app was in urgent need of modernization, with technical debt repayment and bug fixes being a top priority.” While users requested new features, foundation work was prioritized.

Migration to Swift Structured Concurrency

The biggest change is the adoption of Swift structured concurrency and async/await. NetNewsWire’s codebase had been built primarily around Objective-C for many years, and this migration improved the readability and safety of asynchronous operations.

At the same time, the transition to a new user interface style called Liquid Glass UI was completed. Visual refresh was achieved while maintaining compatibility with older OS versions.

Swift Port of Parsers and Resolution of

Technical Debt

The porting of XML, HTML, and date parsers from Objective-C to Swift is also a notable achievement. This increased codebase consistency and improved maintainability. Additionally, numerous bugs, including crash bugs, were fixed. Reductions were achieved in battery consumption, memory usage, hang rate, scroll hitch rate, and disk writes.

Among performance improvements, Simmons particularly emphasized the approach of “reducing the amount of work the app itself does.” By identifying and eliminating unnecessary processes, essential speedups were achieved.

Enhanced Diagnostic Capabilities

Efforts were also made to enable users to self-diagnose problems. Features such as iCloud storage statistics and error logs have already been shipped, and diagnostic tools like “Dinosaurs (恐竜),” “Current Activity (現在のアクティビティ),” “Activity Log (アクティビティログ),” and “Account Stats (アカウント統計)” are in beta.

Simmons explained, “If the app isn’t working as expected, I want users to be able to see what’s going on.” Even if users cannot solve the problem themselves, being able to copy diagnostic information and pass it to developers reduces support time. As a result, more time can be spent on coding and developing new features that users request.

Incidental Improvements and Future Outlook

Other additions include support for Cache-Control headers, allowing feed publishers to adjust the frequency of NetNewsWire’s feed checking. iCloud sync optimization is also progressing, with steady advances despite room for further improvement. API deprecation responses such as the migration to NWPathMonitor have also been implemented.

Simmons stated, “Foundation work is not yet complete, but it’s getting close. Working on this app is much more pleasant than it was a year ago.” He also expressed gratitude to other contributors, while acknowledging that his personal contribution remains the largest.

Editorial Opinion

This update to NetNewsWire contains important implications for the sustainability of open-source projects. The fact that the project has been actively maintained after the developer’s retirement, and even underwent a large-scale refactoring, demonstrates the health of the codebase and the resilience of the committer base.

In the short term, the complete migration to Swift and the enhancement of diagnostic features are expected to improve operational stability on the latest platforms such as iOS 27 and macOS 27. In particular, the addition of diagnostic tools will reduce traditional support burdens and contribute to faster development cycles.

From a long-term perspective, the focus is on whether NetNewsWire can maintain its technical advantage in the relatively niche market of RSS readers. Amid the rise of AI-powered information curation and the general decline of feed distribution, it is uncertain how much demand remains for traditional RSS readers. While modernizing the foundation is essential, it alone does not directly lead to user growth.

The editorial board evaluates Simmons’ design philosophy of “enabling users to self-diagnose problems” as one of the optimal operating models for open-source projects without a large support team. The decision to implement crash log symbolication with a self-contained lightweight system, without relying on commercial products, also reflects a clear intention to avoid increasing dependencies. How the project redefines its value as an RSS reader through future feature additions will likely determine its long-term fate.

References

• NetNewsWire Status - inessential.com — published on 2026-06-15