Criticism
Silverlight has been criticized for keeping Linux out of their official offering. Even though Microsoft is officially collaborating on the Moonlight project, Bruce Chizen, former CEO of Adobe, and maker of direct competitor Flash, has 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 claims, Microsoft has launched products with promises of ongoing cross-platform compatibility that no longer apply.
The international, non-profit European Committee for Interoperable Systems has voiced concerns that with Silverlight Microsoft aims to introduce content on the web that can only be accessed from the Windows platform. They argue that use of XAML in Silverlight is positioned to replace the cross-platform HTML standard. Effectively, if Silverlight usage becomes widespread enough, users will risk having to purchase Microsoft products to access web content.
California and several other U.S. states also have 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.
Microsoft has also been criticized for not using the Scalable Vector Graphics standard for Silverlight, which, according to Ryan Paul of Ars Technica, is consistent with Microsoft's ignoring of open standards in other products, as well.However, according to David Betz, an independent .NET technologies specialist, Microsoft would have needed to alter the SVG specification to add .NET integration and UI constructs on top of SVG to make it suitable for scenarios Silverlight uses markup for (UI and vector markup, by default). Consequently, he thinks the "choice by Microsoft to use XAML over SVG, served to retain the SVG standard by not adding proprietary technology".