OpenSilver 3.3 brings native Blazor into XAML apps

OpenSilver has released version 3.3, adding native support for running Blazor components inside XAML applications.

The open-source framework targets teams that build user interfaces in C# and XAML. It runs those applications in web browsers via WebAssembly. It also supports deployment to iOS, Android, Windows, macOS, and Linux through .NET MAUI Hybrid.

OpenSilver 3.3 adds a way for developers to place Blazor components from third-party libraries directly into XAML views. The company said the integration works without JavaScript bridges or wrapper code.

OpenSilver said the new release works with component libraries from DevExpress, Syncfusion, MudBlazor, Radzen, and Blazorise. The framework also supports other Blazor component libraries, according to the company.

Shared rendering

OpenSilver said the integration relies on both OpenSilver and Blazor rendering to the HTML DOM. That gives both approaches a shared rendering model inside the browser.

Developers can integrate Blazor in two ways, according to the company. One option uses Razor markup written inside XAML files. The other option references standard .razor component files from XAML.

Userware maintains OpenSilver and provides commercial services around application modernisation. The company positioned the new version as an option for organisations that want to combine XAML user interface patterns with the Blazor component ecosystem.

"Blazor has an incredible component ecosystem. XAML has a powerful layout and binding system that developers love," said Giovanni Albani, CEO, Userware.

"With 3.3, you don't have to choose. Use XAML where it excels, drop in Blazor components where you need them. Your ViewModels and architecture stay the same," said Albani.

Component libraries

The release focuses on compatibility with established Blazor vendors and open-source projects. OpenSilver said developers can add a component library package, reference a component, and place it in a XAML view.

DevExpress said it expects the integration to expand options for developers who already use its Blazor components.

"We're pleased to see OpenSilver enabling new scenarios for DevExpress Blazor components," said Alexander Chuev, Blazor Team Product Manager, DevExpress.

"Developers now have more options for building modern applications with familiar tools," said Chuev.

Modernisation use case

Userware said it sees demand from organisations that maintain older Windows presentation layer applications. Many enterprises still run WPF or Silverlight codebases that depend on XAML layouts, bindings, and established application architecture patterns.

OpenSilver provides a route to move those applications to the web through WebAssembly. Userware also described a scenario where teams update parts of an application by swapping controls rather than rewriting a full interface.

The company said the Blazor integration already runs in production at Cegid, a European business software provider. Cegid integrated the DevExpress RichEdit Blazor component into its Tax Flex application, according to Userware. The company said Tax Flex is a large XAML codebase that previously migrated from Silverlight to OpenSilver.

"Adding the RichEdit component was straightforward," said Pascal Olivier, R&D Director, Cegid's Finance Innovation Factory.

"We added the NuGet package, placed the component in our XAML, connected it to our existing ViewModel, and it worked," said Olivier.

Platform updates

Alongside the Blazor work, OpenSilver 3.3 adds platform updates tied to Microsoft's latest .NET toolchain. Userware said OpenSilver 3.3 supports .NET 10, C# 14, and Visual Studio 2026.

The release also introduces a new Responsive markup extension for adaptive layouts in XAML. Userware said it targets scenarios where an application needs different sizes or visibility rules across device classes.

OpenSilver 3.3 also adds more WPF compatibility features, including RoutedCommand infrastructure, template selectors, and preview and tunnelling events, according to the company. Userware also listed additions such as WeakEventManager and DependencyPropertyDescriptor, and it said it rewrote CollectionViewSource.

The company also pointed to updates to layout controls such as Grid and StackPanel. Userware said those controls now support properties including BorderThickness, BorderBrush, Spacing, Padding, and CornerRadius.

OpenSilver 3.3 is available through NuGet, and Userware said it also ships via Visual Studio and VS Code marketplaces through extensions that include a XAML designer and project templates.