‘OpenSilver’ Project Launched, open-source implementation of Silverlight via WebAssembly

March 9th, French software company Userware announced the launch of ‘OpenSilver’ project. It is an open-source reimplementation of Microsoft Silverlight, web browser plug-in technology developed by Microsoft. I can be implemented via WebAssembly.

Userware is a venture company founded by engineers who are adept with Microsoft technologies. They deemed Silverlight the most suitable platform for building rich internet applications for enterprises. However, due to the fact that Microsoft will end support for Silverlight, they launched OpenSilver.

Microsoft initially positioned it as a competitive technology against Flash, but on account of transitioning to HTML5, they announced their plan to end support in 2021.

OpenSilver uses a number of code from CSHTML5, which is a technology to compile C#/XAML to JavaScript/HTML, and it replaces JavaScript with WebAssembly. This enables it to be compatible with .NET.

It is compatible with all browsers that support WebAssembly, like Microsoft Edge, Google Chrome, Firefox, and Safari, and therefore can be used without having to install any specific plug-ins in the web browser. That said, in order to run already existing Silver applications, they need to be recompiled via OpenSilver.

OpenSilver is available on the project website.