Steady progress on our next-gen UI framework. Now supports iOS/Android too, and the 3D TextBox is shaping up. Check out this browser demo powered by #threejs: demo3dui.azurewebsites.net

XAML.io Lets You Build .NET Apps in a Web Browser dlvr.it/TVb0tM

What if AI app builders (Lovable, Bolt, etc.) worked directly on real .NET projects? Introducing XAML.io v0.9: - Prompt, edit, run & publish C# + XAML apps - In-browser .NET IDE with AI + a visual designer - Free to use + free AI credits

We believe app development should feel INSTANT. Meet XAML.io. VB6 feel. Built for today.

Gorgeous!

Big update to XAML.io today: C# IntelliSense/autocomplete is now live. You can now design, build, and run .NET (C# + XAML) entirely in the browser, with a visual designer and WebAssembly compilation. No install. No signup.

OpenSilver is not an emulator, a wrapper, or an Electron-style bundled browser. It is a complete reimplementation of the WPF/Silverlight API from scratch, using modern .NET, WebAssembly, and the browser's DOM. On the Web, your C# code compiles to WebAssembly. Unlike canvas-based rendering approaches, XAML is rendered at runtime using real HTML elements: TextBox becomes <textarea>, MediaElement becomes <video>, PasswordBox becomes <input type="password">, Image becomes <img>, and so on. This unlocks native browser behaviors like Ctrl+F search, text selection (to copy text), screen readers, SEO indexing, browser translation, mobile long-press, UI automated testing, and accessibility compliance. The compiled app is a set of static files (WebAssembly, JS, index.html...) that can be hosted anywhere: Azure, AWS, GitHub Pages, or any basic web server. No special server technology is required. On desktop and mobile (via MAUI-OpenSilver Hybrid or Photino), the UI is still rendered as HTML/CSS, but C# runs as native .NET instead of WebAssembly. This preserves full compatibility with JS libraries and Blazor components (because the UI is still HTML/CSS), while adding native performance and direct access to platform APIs (because the runtime is native .NET).

Blazor components inside XAML. One codebase, six platforms. OpenSilver 3.3 is out.

photo to 3D model

Stunning work. Would love to see a creative coder try an interactive, real-time @threejs version of this masterpiece.

Many people still think OpenSilver is an emulator or wrapper around Silverlight. It is not. We did not inherit any Silverlight code. Silverlight was closed source. We reimplemented the Silverlight/WPF public API from scratch, using modern .NET, WebAssembly, and the browser’s DOM. Why does this matter to WPF developers? Because Silverlight was a backward-compatible subset of WPF. Same namespaces, same XAML, same patterns. This means what began as a Silverlight migration path has naturally evolved into a realistic way to bring WPF-style applications to the web using C#, XAML, and MVVM, without rewriting everything in JavaScript. And here is what most people do not know: OpenSilver does not render everything in a canvas. We render XAML using real HTML elements: • TextBox → <div contenteditable="true"> • MediaElement → <video> • Hyperlink → <a href> • WebBrowser control → <iframe> Why is that a big deal? Because rendering to the DOM unlocks native browser behaviors: Ctrl+F, text selection, screen readers, right click on links, SEO, browser translation, copy and paste, mobile long-press, browser extensions, and regulatory accessibility compliance. You cannot get any of that in a giant canvas rendering model. This is not just “bringing Silverlight to the web”. This is bringing WPF-style architecture to the web, in a truly web-native way. That is why many enterprise teams are migrating, not rewriting.

We really want UIs to go in this direction! Check out this amazing interactive real-time app by @reczko_konrad and @cerpow 👏👏👏

The new Screen-Space Global Illumination (SSGI) effect in the latest #threejs is out of this world🤯👏. We cannot wait to test it inside XR#

Most browser IDEs fake it: the build actually happens on a remote server. XAML.io is different: it compiles .NET GUI apps right in your browser via WebAssembly. No backend at all (except for saving to the cloud or optional AI), which makes it ridiculously scalable.

Userware — the team behind XR# — also builds custom AR/VR apps for clients. Here are 5 highlights of our work:

High-performance WebGPU-based screen-space global illumination using the new SSGINode in #threejs

A Guided Demo of Galaxy XR | Samsung

For the first time, .NET developers can visually build UIs, edit C#, and run apps entirely in the browser — no installs, no setup, no sign-in. The roadmap ahead is 🔥 Follow to stay tuned, and repost to help more devs discover it.

The genius contributors of #threejs are pushing screen-space global illumination to the next level 🤯. Out-of-this-world work👏 - Live test: rawcdn.githack.com/mrdoob/th…

What if you could start coding with .NET in seconds? Now you can: we’ve added C# code-behind to our free online XAML designer, XAML.io 🚀