OpenSilver 3.1 has been released, bringing new features to the open source framework for building web apps using .NET. These include a drag-and-drop XAML designer for VS code, a more modern UI theme, expanded support for Windows Presentation Foundation (WPF) features, and full compatibility with .NET 9.
The new drag-and-drop XAML designer in VS Code includes over 100 ready-to-use controls, such as data grids and charts, and a built-in AI assistant for generating UI layouts.
It also works seamlessly across Windows, macOS, and Linux, making this a major milestone for cross-platform development, as previously XAML UI design was limited to Visual Studio on Windows.
Its new UI theme is more modern and takes inspiration from Material and Fluent Design principles. It includes light and dark modes and the ability to easily adjust color palettes. Additionally, the splash screen that indicates that an application is loading also now has a more modern look.
Developers working on legacy applications will still be able to access original Silverlight themes, the team noted.
Support for several WPF features was added, including DynamicResource, MultiBinding, x:Static, and UniformGrid. The 2025 roadmap includes adding more WPF features, such as triggers and styles.
Other features on the OpenSilver roadmap include MAUI Hybrid integration, Blazor interoperability, and 3D UI support.
“We are committed to supporting the .NET ecosystem by offering tools that help developers build modern web apps and modernize legacy ones efficiently,” said Giovanni Albani, CEO of Userware, the company behind OpenSilver. “OpenSilver bridges legacy and greenfield development, equipping businesses with a forward-looking framework.”