OpenSilver 3.1, the latest iteration of Userware's open-source framework for cross-platform .NET development, has arrived with a groundbreaking feature that promises to transform the way developers create user interfaces. Announced on December 10, the OpenSilver 3.1 SDK brings the first-ever drag-and-drop XAML designer to Microsoft's Visual Studio Code editor, marking a significant milestone in cross-platform .NET development.

Previously, XAML UI design was largely limited to Visual Studio on Windows, leaving developers on macOS and Linux without visual design tools. OpenSilver 3.1 changes this by introducing a fully cross-platform designer, enabling developers to create user interfaces visually in VS Code on any operating system. The designer is available directly in VS Code, with an online version accessible at xaml.io.

As part of Userware's "WPF everywhere" strategy, OpenSilver 3.1 expands support for several Windows Presentation Framework features, including DynamicResource, MultiBinding, x:Static, and UniformGrid. These features aim to make it easier to build feature-rich applications with familiar WPF tools. Userware has announced plans to add more WPF support by mid-2025, including backing for features like triggers and styles.

In addition to the XAML designer and WPF support, OpenSilver 3.1 introduces a modern UI theme inspired by Material and Fluent Design principles. This theme provides a flat, contemporary aesthetic with built-in light and dark modes, enabling developers to create visually appealing web applications. Tools within the XAML designer allow for adjustment of color palettes for branding.

OpenSilver 3.1 is fully compatible with .NET 9 and follows the July release of OpenSilver 3.0, which featured a generative AI-powered UI designer. OpenSilver applications run natively in modern browsers using HTML5 and WebAssembly. Looking ahead, Userware plans to achieve full WPF compatibility, MAUI (Multi-platform App UI) capability for cross-platform apps, Blazor web framework interoperability, and 3D UI support.

The implications of OpenSilver 3.1 are far-reaching, as it democratizes access to visual UI design tools across platforms. This move is expected to boost productivity and creativity among developers, enabling them to focus on building innovative applications rather than wrestling with UI design complexities. As the .NET ecosystem continues to evolve, OpenSilver 3.1 is poised to play a significant role in shaping the future of cross-platform development.

In conclusion, OpenSilver 3.1 represents a major leap forward in cross-platform .NET development, offering a powerful combination of drag-and-drop XAML design, expanded WPF support, and modern UI themes. As the development community begins to explore the possibilities of this new framework, it will be exciting to see the innovative applications and experiences that emerge.