In a significant shift towards transparency and collaboration, Microsoft has transitioned the development of WinUI and the Windows App SDK to GitHub, marking a pivotal moment in its ongoing commitment to enhance its Windows developer technologies. This move is part of a comprehensive strategy that the tech giant unveiled in August 2025, aimed at addressing long-standing developer concerns regarding these previously under-resourced tools.
Open Development Process
A Microsoft engineer elaborated on this transition, stating, “Mainline WinUI development is now taking place on GitHub. WinUI engineers and other Microsoft developers are creating branches, opening pull requests, reviewing, validating, and merging changes right here in this repository.” This approach allows developers to witness the evolution of the project in real time, fostering a sense of community and engagement that was previously lacking.
This initiative represents the fourth phase of Microsoft’s strategic plan to revitalize WinUI and WASDK, which the company now refers to collectively as WinUI. While the technologies have not yet been open-sourced, Microsoft is methodically working towards that goal, ensuring that the development process is more inclusive and responsive to the needs of the developer community.
During the Build 2026 conference in May, Microsoft provided insights into its progress, highlighting its dedication to resolving “pain points” within Windows 11. With the transition to GitHub now complete, the company is focused on refining its development practices. Currently, only Microsoft employees have direct access to modify the codebase, but the plan is to eventually open the repository for community contributions once the system proves effective.
This gradual approach mirrors Microsoft’s earlier efforts to open source legacy Windows developer frameworks, such as Windows Presentation Foundation, Windows Forms, and the Windows UI XAML Library. As Microsoft continues to evolve its development ecosystem, the anticipation builds around the potential for a more collaborative future in Windows application development.