OpenSilver

OpenSilver is a free, open-source UI framework that empowers .NET developers to build modern web applications using the languages and tools they already know — C#, VB, or F#, with XAML for the UI. If you've been frustrated by the need to rewrite perfectly good desktop or Silverlight applications just to get them running in a browser, OpenSilver is the answer. It offers broad compatibility with Microsoft Silverlight and extensive WPF support, so existing codebases can be migrated with far less pain. Applications built with OpenSilver run natively on Windows, Android, Mac, Chrome, Firefox, and Safari, and you get access to enterprise-grade controls and libraries without paying a penny.