News

OpenSilver 3.1 Unveils Drag-and-Drop XAML Designer for VS Code

Claiming an industry first, Userware announced a drag-and-drop XAML designer for use in Visual Studio Code, coming with OpenSilver 3.1, the latest iteration of the open-source implementation of Microsoft's long-deprecated and oft-mourned rich client development platform, Silverlight.

OpenSilver 1.0 arrived in 2021 just as Microsoft ended support for Silverlight, a browser plug-in primarily used to create Rich Internet Applications, providing functionality similar to Adobe Flash such as playing music, videos, animations and so on.

The Paris-based Userware today (Dec. 10) announced version 3.1, with the highlight being the XAML designer, previously available only in Microsoft's full-fledged Visual Studio IDE.

"Until now, XAML UI design was largely limited to Visual Studio on Windows, leaving developers on macOS and Linux without visual design tools," the company said. "OpenSilver 3.1 changes that by introducing a fully cross-platform designer, enabling developers to create complex user interfaces visually in VS Code -- on any operating system."

While the designer comes in a downloadable SDK .vsix file for use in VS Code, the company also published it online for users to try out immediately, shown here:

Online XAML Designer
[Click on image for larger view.] Online XAML Designer (source: Userware).

Other highlights of the release noted by the company include:

  • Enhanced "WPF Everywhere" support: New features include:
    • DynamicResource
    • MultiBinding
    • x:Static
    • UniformGrid
  • Support for .NET 9: Support in the brand-new .NET 9 helps OpenSilver applications helps applications run natively in modern browsers using WebAssembly and HTML5, with no need for plugins or additional installations.
  • Modern UI theme: This is inspired by Material and Fluent Design principles, offering a flat aesthetic with light and dark modes for contemporary web applications. The theme supports easy customization via the XAML designer, enabling quick color palette adjustments for branding. The default splash screen has also been updated. For legacy applications, the original Silverlight theme is still available to ensure seamless, pixel-perfect migrations.
  • Going forward, the company said, future updates include:

    • Full WPF compatibility: Expanding support for triggers, advanced styles, and more.
    • MAUI Hybrid integration: Combine native and web technologies to build cross-platform apps for Windows, macOS, iOS, and Android.
    • Blazor interoperability: Mix and match Blazor components with XAML in the same project.
    • 3D UI support: Early previews of this feature are already available at XRSharp.io

    About the Author

    David Ramel is an editor and writer at Converge 360.

    comments powered by Disqus

    Featured

    • Microsoft Highlights Visual Studio Live! Event Lineup and Longtime Developer Community Role

      A Microsoft MVP Blog post on Visual Studio Live!'s longevity arrives as the 2026 conference series continues with upcoming stops at Microsoft HQ, San Diego and Orlando.

    • Using Local AI to Cut Copilot Usage-Based Billing Shock

      After being gobsmacked by the new billing plan using almost all my monthly credits in one or two days, I tried pushing some Copilot-style coding work onto local models in VS Code. What I found was less "free AI" and more "pick your pain": cloud charges on one side, heavy local resource use and long waits on the other.

    • .NET 11 Preview 5 Focuses on Performance, Productivity and Safer Code

      .NET 11 Preview 5 focuses on under-the-hood runtime performance gains, streamlined APIs and language features that reduce boilerplate, plus built‑in security checks and incremental ASP.NET Core and EF Core improvements aimed at everyday developer productivity.

    • VS Code 1.124 Focuses on Agent Autonomy and Parallel Sessions

      Microsoft's June 2026 VS Code update turns on Autopilot by default and adds background sending for agent sessions.

    Subscribe on YouTube