Declared "dead" by developers 17 months ago, Microsoft suddenly officially announced that WinUI with 6,800 Stars will be "truly open - sourced". Netizens questioned: Is it trying to rely on external support to stay alive?

A project that was already "open-sourced" many years ago has now announced it will be "truly open-sourced." What kind of trick is Microsoft playing?

All along, Microsoft has been waving the flag of "Microsoft ❤️ Open Source." From the source code of the antique MS-DOS 4.0 to the open-sourcing of WSL, it has indeed released quite a few achievements. However, what has sparked controversy this time is WinUI, which has been on GitHub for years and is defined as the modern UI framework for the Windows system.

The incident started with a recent announcement on GitHub by Beth Pan, the chief software engineer at Microsoft. She stated that WinUI is "gradually moving towards true open-source collaboration." As soon as these words were out, many developers were confused and said, "Wasn't it already open-sourced long ago? Why is it happening again?"

What's even more ironic is that right after this announcement was a discussion post initiated by a developer 17 months ago, with the title reading, "WinUI 3 is dead. When can we expect an official announcement?" This post has now accumulated over 580 comments, becoming a central outlet for the community's dissatisfaction with the project's stagnant progress.

After all, developers' disappointment with WinUI has been building up for years. Now that Microsoft is shouting the slogan of "true open source," is it sincerely turning to embrace the community, or is it just too busy to handle it alone and is calling on more external developers to get involved? This question might be more worthy of attention than WinUI itself.

01 The Chaos of WinUI's "Open Source"

Put simply, WinUI is a modern native UI framework launched by Microsoft, mainly used to build desktop application interfaces on Windows 10 and 11. It also inherits part of the technical route of the past UWP. It provides a complete control library and style support, following the Fluent Design system, allowing developers to create more modern and unified Windows application interfaces.

Microsoft positions it as "the modern native UI platform for Windows" and integrates it into some system-level applications, such as the "Settings" interface. It also supports new development methods like React Native for Windows and is one of the important tools for Microsoft to promote the modernization of the Windows application ecosystem.

When we open the GitHub address of WinUI (https://github.com/microsoft/microsoft-ui-xaml), we find that it already has 6.8k stars. So what exactly does Microsoft mean by "truly open-sourcing it in the future"?

Actually, the title of the announcement released by Beth Pan reads - "WinUI Open Source Update: Gradually Promoting Open Collaboration." In the eyes of the outside world, they want to change the development process of WinUI, especially how to manage their own GitHub repository (repo).

Currently, this repository is just a "regularly synchronized copy" of their internal code. That is to say, Microsoft's engineers actually still develop in the internal repository, and the one on GitHub is just an irregularly updated version for people to see.

What they want to do next is to make the GitHub repository the main development repository, where all developers (both internal and external to Microsoft) can directly submit code and make contributions.

This is what they mean by "truly open-sourcing this repo."

02 Four Steps to Promote the "True Open Source" of the Windows 11 User Interface Framework

As for when this promise will be fulfilled, Beth Pan, the chief software engineer at Microsoft, admitted that she wasn't sure. She only said, "Many people have raised questions about the issue of 'truly open-sourcing this codebase.' Although we can't promise a specific timeline for completing all the milestones at present, we can clearly tell everyone that we are actively promoting it. This won't be an instantaneous 'one-click switch' but a gradual process."

As mentioned above, most of the WinUI code is only regularly mirrored and synchronized to GitHub, and the main repository is still private within Microsoft. In the announcement, Pan listed four stages for opening this repository:

Stage 1: Increase the Frequency of Mirror Synchronization

After the release of Windows App SDK 1.8 (at the end of August), Microsoft will start to synchronize internal commits to GitHub more frequently to enhance transparency and show the latest progress of the project.

Stage 2: Third-Party Developers Can Build Locally

External developers will be able to clone the repository and build it locally. We will also provide documentation to guide environment configuration and dependency management.

Stage 3: Third-Party Developers Can Contribute and Run Tests

Contributors will be able to submit PRs and run tests locally. Microsoft is working hard to strip private dependencies and open the test infrastructure to the community.

Stage 4: GitHub Becomes the Main Development Ground

GitHub will become the main platform for development, issue tracking, and community interaction. The internal repository mirror will be gradually phased out.

She said, "The reason this process is complex is that WinUI is deeply coupled with the Windows system. Some code directly depends on proprietary underlying components that cannot be made public. We are working hard to separate the shareable parts from the non-shareable parts - this work is still in progress and will take some time."

Beth Pan also pointed out, "This work is being carried out in parallel with other important responsibilities, such as security assurance, platform stability, and support for existing products. Currently, our focus is on laying a solid foundation to enable contributors to truly participate, while enhancing the transparency of the entire project. We are also ensuring that this work is consistent with Microsoft's broader business strategy to gain long-term support and influence."

Meanwhile, she also called on developers who are enthusiastic about WinUI 3 to actively participate. "We know this might not be all that you want to hear, but we hope this shows that we are serious and willing to do this well."

03 Developers: Microsoft Has Launched Multiple UI Frameworks

Many developers aren't convinced by this statement. Some think Microsoft is too "changeable" in its UI development technical route.

Just looking at Microsoft's UI technology development route over the years:

Win32 (1985): It is the built-in API for Windows. With it, you can create buttons, windows, scroll bars, call the system shell, and use common dialog boxes. The generated interface looks and behaves like a native window. Although it's an old technology, it can be accessed with the C language and is still in use today.

MFC (1992): It is a C++ wrapper for Win32, making the API a bit easier to use. Microsoft still makes minor updates to MFC, and it is still widely used.

WinForms (2002): It is a .NET wrapper for Win32, used by .NET languages like C#. It is currently in maintenance mode, and no new features are planned to be added.

WPF (2006): It introduced XAML and draws vector components based on DirectX, used by .NET languages (such as C#). It is now open-source.

Silverlight (2007): It borrowed some technology from WPF and was used to create UIs on the web. It was once a competitor to Adobe Flash and is now discontinued.

Xamarin (Forms, 2014): It is a cross-platform .NET solution, and Xamarin.Forms is its UI framework (a bit like WinForms). It initially ran on Mono and later migrated to the official .NET and has been replaced by MAUI.

WinJS (2012): It is a JavaScript-based framework used to create Windows Store applications through HTML5 and JavaScript. It seems to have stopped development.

WinRT (XAML, 2012): It is an application platform that can use custom C++ language variants (such as C++/WinRT, C++/CX) combined with XAML to build user interfaces. It was later replaced by UWP.

UWP (XAML, 2015): It is the "universal application" platform launched since Windows 10, supporting native C++ and .NET language development. It was later replaced by WinUI.

WinUI (2018): It is similar to UWP but has a style closer to Windows 11. It was later succeeded by WinUI 3.

MAUI (2020): It is a multi-platform UI development framework and the successor to Xamarin.Forms. It is also based on XAML and only supports .NET languages.

WinUI 3 (2021): It is similar to WinUI but separates the UI framework from the operating system and becomes an independent library. That is to say, your application can use it even on an unupdated system.

Every few years, Microsoft launches a new technology to replace the old one, but many are eventually partially or completely abandoned. Their constant name changes and different approaches have left many developers confused. Of course, "changeability" is just one factor.

On the other hand, based on WinUI 3, Microsoft launched an integration project called Project Reunion to bridge the "generation gap" among developers. Whether you're an old-school Win32 developer or a "new force" betting on UWP, you can use it under this framework.

Project Reunion was later renamed the current Windows App SDK (WASDK), and WinUI 3 has become one of its important components. It not only continues to support Fluent Design but also shoulders the important task of unifying the Windows application interface experience.

However, recently, many developers have flocked to social media to complain about the lack of openness of WinUI 3. Some even bluntly said, "Even Microsoft itself doesn't use it. How can it expect the community to use it?"

A senior developer also commented:

I started using WinRT since the Windows 8 era. Then I've been following Microsoft's constant changes: first UAP, then UWP, then C++/CX was replaced by C++/WinRT without tool support, and later there were XAML Islands, XAML Direct, and the initially well-promoted Project Reunion, the restart of WinAppSDK, the chaotic switch between WinUI 2.0 and 3.0, and the on-again-off-again situation of .NET Native...

I've also followed every community meeting (mostly on YouTube).

My advice is: Don't touch WinUI 3.0. The current experience is still terrible, even worse than the previous UWP, and UWP wasn't much better than WPF in the first place.

Those key figures in the community have either jumped to competitors or been transferred to other departments within Microsoft.

You can go and take a look at Microsoft's public project repositories on GitHub, and the issue reports and submission activity will tell you everything.

Perhaps seeing everyone's feedback, Beth Pan also wrote in this announcement, "Thank you for all your feedback, questions, and suggestions. We've fully heard your voices and are taking them seriously. In the next 6 months, we will enter a new phase focused on improvement, including product-level optimizations and some fundamental changes to support a more open and collaborative future."

04 "Is WinUI Trying to Survive with the Help of the Community?"

Pan's open-source statement has won the approval of some developers - "It's reassuring that WinUI is still active and being cared for." However, more people are skeptical about whether Microsoft will truly invest enough resources and build developers' confidence.

"I've been deeply involved in WinUI development for years," said a developer.

To be honest, I don't think Microsoft realizes the harm it has caused to evangelists, the large developer community, and even the companies that have adopted WinRT→UWP→WinUI/WASDK. The continuous stagnation and false promises have been exhausting. Even now, we still don't have a usable solution for input validation, and basic things like modal dialog boxes still have various bugs. Under such limitations, how can enterprise-level applications (LOB) operate?

Our company has been developing Windows clients since the Windows 3.0 era. Now we no longer prioritize Windows platform development. The reason is simple: lack of transparency, lack of progress, lack of responsibility, and lack of a clear direction.

If we count from its initial form in the Windows 8 era, WinUI is almost 15 years old (I even suspect that some parts of it can be traced back to the DirectUI in the XP era). Compared with Apple's operating system, it lags behind by several orders of magnitude. Why can Apple iterate quickly and continuously bring new features, while WinUI is still full of defects and bugs?

I'll also add a few more questions:

Almost 18 months have passed, and developers are completely disappointed with Microsoft's lack of transparency and communication. Everyone is saying, "WinUI 3 is really dead!" This question was submitted in March 2024, and there are already 580 comments below. Why did it take so long for someone to respond?

Is Microsoft planning to let the community develop the platform for them since they've hardly made any investment themselves?

When will Microsoft start seriously categorizing issues and updating the backlog?

Can Microsoft promise not to "batch close" thousands of issues at once?

How is this so-called "change of direction" different from the "we'll do things differently" statements in the past few years? And will it really bring actual progress?

When will there be an updated roadmap?

Please forgive my cynicism - I sincerely hope this project can succeed, but based on what I've seen over the years, I don't have high hopes.

Another developer even said, "The entire WinRT (including the subsequent WinUI) was a mistake from the start." He mentioned that the fragmentation of the Windows development ecosystem started when Microsoft introduced WinRT in Windows 8 and the practice of making C++ and .NET languages interoperable through "language projection."

Some netizens also left comments:

To be honest, this looks like outsourcing the remaining parts of WinUI. I can only wish good luck to those who still believe that Microsoft is serious about WinUI. You've never been serious. Since Windows 8, the cost of that entire toolchain and rewriting has been extremely high, and it has completely exhausted the goodwill that the Windows developer community originally had towards Microsoft. Now there's hardly any reason for an enterprise to use WinUI as the foundation for its new applications. Even now, it hasn't even reached the functional level of UWP back then.

Although the open-sourcing of WinUI is a positive sign, the more crucial thing is how much resources Microsoft is willing to invest to truly support it. "How many people are working full-time on WinUI or WinAppSDK?" another developer questioned. "It now seems that Microsoft's focus has completely shifted to the web, and other things are just being maintained."

What do you think of Microsoft's latest move regarding WinUI?

References:

https://github.com/microsoft/microsoft-ui-xaml/discussions/10700

https://www.theregister.com/2025/08/05/microsoft_winui_open_source/?td=rt-3a

https://irrlicht3d.org/index.php?t=1626

This article is from the WeChat official account "CSDN", written by Tu Min, and published by 36Kr with permission.