|Initial release||September 5, 2007|
|Final release||5.1.50918.0 (January 15, 2019 )|
|Operating system||Microsoft Windows, macOS, and Symbian OS|
|Platform||IA-32 and x86-64|
|Type||Application framework, run-time environment and multimedia framework|
Microsoft Silverlight (or to simplify Silverlight) is a deprecated application framework designed for writing and running rich web applications, similar to Adobe's own runtime, Adobe Flash. A plugin for Silverlight is still available for a very small number of browsers. While early versions of Silverlight focused on streaming media, later versions supported multimedia, graphics, and animation, and gave support to developers for CLI languages and development tools. Silverlight was also one of the two application development platforms for Windows Phone, but web pages using Silverlight did not run on the Windows Phone or Windows Mobile versions of Internet Explorer, as there was no Silverlight plugin for Internet Explorer on those platforms.
Microsoft plans to terminate support for Silverlight on Internet Explorer 11 (the last remaining web browser still supporting Silverlight) on October 12, 2021. It is supported on Windows 8.1 and later and Windows Server 2012 and later, and e.g. Windows Embedded POSReady 7 and Windows Thin PC, while e.g. Windows 7 and earlier do not get security updates.
According to statowl.com, Microsoft Silverlight had a penetration of 64.2% in May 2011. Usage on July 2010 was 53.6%, whereas as of May 2011 Support of these plugins is not mutually exclusive; one system can support all three.market leader Adobe Flash was installed on 95.3% of browsers, and Java was supported on 76.5% of browsers.
Silverlight was used to provide video streaming for the NBC coverage of the 2008 Summer Olympics in Beijing, the 2010 Winter Olympics in Vancouver, and the 2008 conventions for both major United States political parties. Silverlight was also used by Amazon Video and Netflix for their instant video streaming services, but Netflix said in its Tech Blog in 2013 that, since Microsoft had announced Silverlight's end-of-life, they would be moving to HTML5 video.
Industry observers had announced the death of Silverlight as early as 2011. Internally, even proponents of the technology thought Extensible Application Markup Language as a concept was a bad idea from the start.
In 2012, Microsoft deprecated Silverlight for HTML5 in Windows 8, but as late as the beginning of 2015, it was not clear what Microsoft's official position was on the future of Silverlight as a technology.
In July of 2015, a Microsoft blog post finally clarified matters: "... we encourage companies that are using Silverlight for media to begin the transition to DASH/MSE/CENC/EME based designs". Microsoft plans to terminate Silverlight support on October 12, 2021. Support for IE7-8 was removed between 2014 and 2016, depending on the OS. Support for IE9 and IE10 has also ended "or though [sic] the support lifecycle of the underlying browsers, whichever is shorter." There is no Silverlight plugin available for Microsoft Edge. It has not been supported by Google Chrome since September 2015 or by Firefox since March 2017.
Silverlight provides a retained mode graphics system similar to Windows Presentation Foundation (WPF), and integrates multimedia, graphics, animations, and interactivity into a single run-time environment. In Silverlight applications, user interfaces are declared in Extensible Application Markup Language (XAML) and programmed using a subset of the .NET Framework. XAML can be used for marking up the vector graphics and animations. Silverlight can also be used to create Windows Sidebar gadgets for Windows Vista.
Silverlight supports H.264 video, Advanced Audio Coding, Windows Media Video (WMV), Windows Media Audio (WMA), and MPEG Layer III (MP3) media content across all supported browsers without requiring Windows Media Player, the Windows Media Player ActiveX control, or Windows Media browser plug-ins. Because Windows Media Video 9 is an implementation of the Society of Motion Picture and Television Engineers (SMPTE) VC-1 standard, Silverlight also supports VC-1 video. According to the end user license agreement VC-1 and H.264 are only licensed for the "personal and non-commercial use of a consumer". Silverlight makes it possible to dynamically load Extensible Markup Language (XML) content that can be manipulated through a Document Object Model (DOM) interface, a technique that is consistent with conventional Ajax techniques. Silverlight exposes a Downloader object which can be used to download content, like scripts, media assets, or other data, as may be required by the application. With version 2, the programming logic can be written in any .NET language, including some nuclear evolution of common dynamic programming languages like IronRuby and IronPython.
A free software implementation (now abandoned) named Moonlight, developed by Novell in cooperation with Microsoft, was released to bring Silverlight version 1 and 2 functionality to Linux, FreeBSD, and other open source platforms, although some Linux distributions did not include it, citing redistribution and patent concerns. However, in May 2012, Moonlight was abandoned because of its lack of popularity.
Over the course of about five years, Microsoft had released five versions with varying platform support: The first version was released in 2007, and the fifth (and final) major version on May 8, 2012. It is compatible with later versions of Internet Explorer web browser on Microsoft Windows (except Windows RT) operating systems, with Safari on Apple macOS, and with mobile devices using the Windows Mobile and Symbian (Series 60) platforms.
Cross-platform Mozilla Firefox support for Silverlight was removed in Firefox 52 released in March 2017 when Mozilla removed support for NPAPI plugins, bringing it in-line with the removal of NPAPI plugin support in Google Chrome.
The following table presents an availability and compatibility matrix of Silverlight versions for various operating systems and web browsers.
|This version of Silverlight is currently supported on the given platform + browser combination.|
|Silverlight support on the given platform + browser combination has expired.|
|No Silverlight version has ever been supported on the given platform + browser combination.|
|The given platform + browser combination does not exist.|
|Web browser||Internet Explorer 6 SP1 or later||Internet Explorer 7||Internet Explorer 8 and 9||Internet Explorer 10||Internet Explorer 11||Firefox||Safari||Chrome||Edge||Opera|
|Windows 11||N/A||N/A||N/A||N/A||N/A||None, since Firefox 52||1, 2||None, since Chrome 45||None||None|
|Windows 10||N/A||N/A||N/A||N/A||5||None, since Firefox 52||1, 2||None, since Chrome 45||None||None|
Windows Server 2012 or later
|N/A||N/A||N/A||N/A||5||None, since Firefox 52||1, 2||None, since Chrome 45||None||None|
|Windows 8||N/A||N/A||N/A||5||N/A||None, since Firefox 52||1, 2||None, since Chrome 45||None||None|
Windows Server 2008 R2
|N/A||N/A||1, 2, 3, 4, 5||None||5||None, since Firefox 52||1, 2||None, since Chrome 45||None||None|
Windows Server 2008
|N/A||1, 2, 3, 4, 5||1, 2, 3, 4, 5||N/A||N/A||1, 2, 3, 4, 5[note 1]||1, 2||None, since Chrome 45||N/A||None|
Windows Server 2003
|1, 2, 3, 4||1, 2, 3, 4, 5||1, 2, 3, 4, 5||N/A||N/A||1, 2, 3, 4, 5[note 1]||1, 2||None, since Chrome 45||N/A||None|
|2, 3, 4||N/A||N/A||N/A||N/A||N/A||2||N/A||N/A||None|
|macOS (Intel)||N/A||N/A||N/A||N/A||N/A||None, since Firefox 52||None, since Safari 12||None, since Chrome 45||None||None|
|Ubuntu Linux||N/A||N/A||N/A||N/A||N/A||None, since Firefox 52||N/A||None, since Chrome 45||None||None|
Support for Opera had been promised since May 3, 2007, when David Storey, the Chief Web Opener at Opera, revealed a Microsoft poster for MIX conference that had shown Opera integration as a part of Silverlight 1.1. However, Opera was never officially supported by Silverlight.
On Linux and FreeBSD, the functionality was available via Moonlight and Pipelight, though both projects have since been discontinued. Moonlight is available for the major Linux distributions, with support for Firefox, Konqueror, and Opera browsers, provided it was obtained through Novell. Miguel de Icaza has expressed an interest in working with developers from other operating systems (BSD, Solaris) and other browsers (Konqueror, WebKit and Opera) to ensure that Moonlight works fine on their systems. Availability of Moonlight version 1.0 for FreeBSD was announced in March 2009, but has since been reported not to actually work. As of 2011 , the current version of Moonlight (4 Preview 1) does not officially work on new versions of Firefox (newer than 3.x) on Linux-based operating systems. However, it can be installed in an unofficial way (for example using the Add-on Compatibility Reporter add-on) and with Firefox 11 it works correctly when installed. As noted above, the Moonlight project was abandoned in May 2012.
A browser plugin named Pipelight used to provide Silverlight access. Pipelight requires browser support for NPAPI plugins, which newer versions of Firefox, Chrome, and Opera have dropped. As of 2018, the Pipelight project has been discontinued.
Silverlight was the primary development environment for Windows Phone (that is by now discontinued) and is based on Silverlight 4. For previous versions of Windows Mobile, the first Community Technology Preview (CTP) for Windows Mobile 6 was expected in the second quarter of 2008, but it still has not been officially announced. Microsoft has stopped focusing on bringing Silverlight to Windows Mobile 6.x. Nokia announced plans to make Silverlight for Mobile available for S60 on Symbian OS, as well as for Series 40 devices and Nokia internet tablets (while it later sold the business to Microsoft and now sells Android tablets and will sell Alcatel-Lucent branded smartphones). Silverlight for Mobile supports Silverlight 2 content and .NET languages. Silverlight for Windows Phone 7.5 is based on Silverlight 4.
Silverlight applications could be written in any .NET programming language. As such, any development tools which can be used with .NET languages can work with Silverlight, provided they can target the Silverlight CoreCLR for hosting the application, instead of the .NET Framework CLR. Microsoft has positioned Microsoft Expression Blend as a companion tool to Visual Studio for the design of Silverlight User Interface applications. Visual Studio can be used to develop and debug Silverlight applications. To create Silverlight projects and let the compiler target CoreCLR, Visual Studio requires the Silverlight Tools for Visual Studio.
A Silverlight control is a ZIP format file with extension .XAP containing a list of one or more .NET managed assemblies (.DLL files) along with the AppManifest.XAML file containing this list along with the entry point (class and assembly). It can be hosted in any HTML file using an object tag, for example:
<object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%"> <param name="source" value="MySilverLightControl.xap"/> </object>
A Silverlight project contains the Silverlight.js and CreateSilverlight.js files which initializes the Silverlight plug-in for use in HTML pages, a XAML file for the UI, and code-behind files for the application code. Silverlight applications are debugged in a manner similar to ASP.NET applications. Visual Studio's CLR Remote Cross Platform Debugging feature can be used to debug Silverlight applications running on a different platform as well.
An April 2007 PC World report, suggested that Microsoft intended to release certain parts of Silverlight source code as open source software, but a week later Sam Ramji, director of platform technology strategy at Microsoft, contradicted the rumors by confirming that the company had no plans to open Silverlight. Some controls that ship with Silverlight are available under the Microsoft Public License as a part of a separate project known as the Silverlight Toolkit.
Silverlight's proprietary nature is a concern to competition since it may harm the open nature of the World Wide Web. Advocates of free software are also concerned Silverlight could be another example of Microsoft's embrace, extend, and extinguish strategy. Both Microsoft Silverlight and Adobe Flash are proprietary. Flash's file formats are publicly documented standards, as are Silverlight's. Silverlight, like other web technologies, uses patent-encumbered audio and video codecs.
The Mono Team abandoned development of Moonlight, a free and open-source implementation of both the Silverlight 1 and 2 runtimes. Development was discontinued in 2012 due to the poor acceptance of Silverlight and the restrictions imposed by Microsoft.
The project had been officially supported by Microsoft which, under an agreement with Novell, made not-publicly-available additional specifications, access to the Silverlight Base Class Library APIs, binary codecs and test cases available to the Mono team.
The "covenant" under which Novell was granted this exclusive access also specified conditions incompatible with the licensing that covers most free and open source software. As examples, it specifically required that the software must have been "obtained directly from Novell or through an Intermediate Recipient" and that it must be "not licensed under GPLv3 or a Similar License". Some free software proponents criticized the covenant.
Silverlight was criticized for not living up to its cross-platform operating system compatibility promises, especially on Linux systems, compared to its extensive support on Apple and Microsoft desktops for Internet Explorer, Firefox, and Chrome. Although Microsoft was officially collaborating on the Moonlight project, Bruce Chizen, CEO of Adobe Systems, which sells the competing proprietary Flash platform, questioned "the commitment of Microsoft to keep the Silverlight platform compatible with other OS besides Windows". His concerns are based on "examples from history" where he said that Microsoft had launched products with promises of ongoing cross-platform compatibility that no longer apply, for example Internet Explorer for UNIX and Windows Media Player for Mac.
In 2007, California and several other U.S. states asked a district judge to extend most of Microsoft's antitrust case settlement for another five years, citing "a number of concerns, including the fear that Microsoft could use the next version of Windows to 'tilt the playing field' toward Silverlight, its new Adobe Flash competitor," says a Seattle Post-Intelligencer article. The final judgment on the motion extended the settlement two years, to November 2009, but for reasons unrelated to Silverlight.
we encourage companies that are using Silverlight for media to begin the transition to DASH/MSE/CENC/EME based designs
Beginning January 12, 2016, only the most current version of Internet Explorer available for a supported operating system receives technical support and security updates
"Downstream Recipient" means an entity or individual that uses for its intended purpose a Moonlight Implementation obtained directly from Novell or through an Intermediate Recipient... Microsoft reserves the right to update (including discontinue) the foregoing covenant... "Moonlight Implementation" means only those specific portions of Moonlight 1.0 or Moonlight 1.1 that run only as a plug-in to a browser on a Personal Computer and are not licensed under GPLv3 or a Similar License.
We will be supporting Firefox and Linux initially (that is our first goal) but we are looking forward to work with developers from other operating systems (BSD, Solaris) and other browsers (Konqueror, WebKit and Opera) to ensure that Moonlight works fine on their systems.
Version 1.0; Applies To: Windows® Phone 7
Silverlight for Windows Phone OS 7.1 is based on Silverlight 4. That means if you create a new Silverlight for Windows Phone application that targets Windows Phone OS 7.1, you can take advantage of several new features.
Others take a darker view of Microsoft's intentions and argue that Silverlight is simply a rehash of the company's 1990s-era "embrace and extend" strategy for pre-empting Web competition. "They're still playing the same games," said Michael Nelson, professor of internet studies at Georgetown University. "It's a way to lock up the content, and it's not enabling as much innovation as we would like to see."
Companies building websites should beware of proprietary rich-media technologies like Adobe's Flash and Microsoft's Silverlight, the founder of Mozilla Europe has warned.
Moonlight is safe from threat only if you get it from Novell AND DO NOT PASS IT ON, as there are no protections for downstream recipients...Unless those downstream recipients get it from an 'Intermediate Recipient' defined to only include authorized resellers...It's like walking into a store and saying "I'm only going to pay half of the amount I owe and I hereby disclaim my duty to pay full price." You can try that, but the law supersedes whatever intent or desire you've expressed. At minimum, this shows how clearly they DO NOT want to coexist with GPL'd code.