Silverlight
Silverlight was a Microsoft browser plugin technology for delivering rich, app-like experiences on the web at a time when browsers lacked modern capabilities. It enabled video, animation, and sophisticated user interfaces inside the browser using XAML and C#. In its era it powered streaming media and internal business tools that needed more than basic web pages could provide.
Official WebsiteMigration Guidance
Silverlight is end-of-life and unsupported by current browsers. Migration is strongly recommended to modern web standards (HTML5/JavaScript/TypeScript with frameworks like React or Vue) or to desktop alternatives (WPF/.NET) depending on the use case. Continuing on Silverlight creates security, compatibility, and staffing risks and blocks future improvements.
When to use Silverlight
Only use Silverlight for maintaining legacy systems that still depend on it and cannot be immediately replaced. It's no longer supported in modern browsers, so usage is limited to controlled environments with older setups.
Why choose Silverlight?
Silverlight was chosen historically to deliver rich media and interactive apps when HTML and JavaScript were immature. It offered consistent behaviour across browsers, strong tooling, and a familiar model for .NET teams.