Microsoft Silverlight is a discontinued application runtime and browser plug-in for interactive web applications and media on Windows and Mac. It supplies the graphics, controls and code execution that applications built for Silverlight need. The plug-in is free, while creating those applications requires separate development tools. Silverlight has reached the end of support, and Microsoft Edge does not run its browser plug-in.
XAML interfaces and .NET code
Silverlight applications describe their visual elements in XAML, a markup language for arranging controls, text, images and graphics. Application code supplies the behavior behind those elements. This lets a developer combine a form or list with animation and custom graphics, then respond to keyboard and mouse input within the same interface.
The rendering system handles vector shapes as well as bitmap images. Controls can be styled and given different visual templates, while layout rules position them as the interface changes. Deep Zoom adds navigation through high-resolution imagery, letting an application offer panning and magnification instead of displaying only a fixed-size picture.
Microsoft Silverlight includes a subset of the .NET Framework, with support for application logic written in languages such as C# and Visual Basic. Its runtime manages memory and handles exceptions as that code executes. The available interface and behavior come from the application being loaded; installing Silverlight alone does not create a form designer or a graphics editor.
Media playback
An application can load audio or video by supplying a media address to Silverlight’s MediaElement component. It handles supported MP4, Windows Media and MP3 content, and application developers can connect it to play, pause, stop and volume controls. They can also change the playback position and decide how video fits its display area.
Media can interact with the rest of the interface. Timeline markers identify points in a recording, and reaching a marker can trigger application code, such as changing accompanying text or moving to a named scene. Server-side playlists let a content service determine the sequence of streamed items. Silverlight also supports PlayReady-protected media, with playback governed by the service’s licensing system.
Web services and page integration
Silverlight applications can request information from web services and work with formats including XML and JSON. Data binding connects the resulting objects to controls, so an application can update displayed information without reloading the entire host page. Its .NET libraries also provide tools for querying and processing data, including LINQ and XML handling.
When Silverlight is embedded in a web page, the HTML Bridge allows its managed code and the page’s JavaScript to communicate. The host page can also pass initialization values into the application.
Silverlight outside the browser
Applications configured for out-of-browser use can open in a separate desktop window and launch through shortcuts. This capability depends on the application’s configuration; it does not automatically convert every embedded Silverlight component into a desktop program.
Offline work likewise depends on how the application was built. It can keep data in isolated local storage, detect a lost connection and use cached information until its server is available again. An application can then synchronize that data when connectivity returns. Features that rely on the host page or uncached online content still need their original resources.
Ordinary desktop applications retain Silverlight’s security restrictions. Applications configured for elevated trust can obtain additional capabilities, including access to local files and more control over their windows.
