Moonlight 4 Preview Launched

The open-source Mono Project sponsored by Novell has delivered Moonlight 4, the latest version of the Linux implementation of Microsoft's Silverlight.

Novell's open-source Mono Project has delivered a preview version of Moonlight 4, the latest version of the Linux implementation of Microsoft's Silverlight developer platform.

This release gives Firefox and Google Chrome users on Linux access to the latest Silverlight content and enables developers to take advantage of the newest features of Silverlight on all platforms.

In a statement, Miguel de Icaza, Mono Project founder and Developer Platform vice president at Novell, said, "Our team has worked tirelessly to get Moonlight to version parity with Silverlight 3-finally bringing the latest development and delivery capabilities for visually rich applications to Linux. Now that we've reached this milestone, we are looking to complete the 4.0 APIs."

Having delivered Moonlight with full support for all prior versions of Silverlight and preview support for Silverlight 4, including support of Microsoft-licensed codecs for Silverlight 3 and 4, the delivery of the Moonlight 4 preview marks the first time the Moonlight project has shipped a release consistent with many popular sites built for the latest release of Silverlight.

Meanwhile, Microsoft is at work on Silverlight 5, the next version of Silverlight that is expected to appear in beta some time during the first half of 2011. Silverlight 5 introduces more than 40 new features, including support for running Silverlight applications with desktop features in the browser, video quality and performance improvements, and features that improve developer productivity.

"We are always working to provide solutions that software development teams need to be productive and deliver applications quickly and cost-effectively," said Nikolay Atanasov, product manager for RadControls for Silverlight at Telerik, in a statement. "With the availability of the Moonlight 4 beta, and its compatibility with Telerik RadControls for Silverlight, developers now have even greater flexibility to rapidly develop applications for Silverlight, while being able to build and deliver their applications on time and in budget."

Moreover, with the new preview, developers can also leverage the Silverlight 3 APIs and numerous Silverlight 4 APIs, including support for the H.264 video codec, hardware acceleration of graphics rendering using the GPU, 3D transformation and pixel shaders. It also extends Web browser support to Google Chrome and contains numerous performance and memory management improvements. In addition, users can run Silverlight applications as desktop applications on Linux in both "sand-boxed" and full-trust modes using Moonlight's unique mopen command.

"The latest release of Moonlight is another important step forward in creating a compatible open-source implementation of Silverlight," said Brad Becker, director of product management at Microsoft, in a statement. "By enabling support for Linux, Moonlight 4 gives Silverlight developers the tools they need to develop for the platforms they want to."

To download the Moonlight 4 beta or learn more about the project, visit For more information about open-source projects that Novell sponsors and contributes to, visit

Moonlight is part of a technical collaboration announced by Novell and Microsoft in September of 2007. Microsoft has provided Novell with access to its test suites and specifications for Silverlight, and provides Novell end users of Moonlight with free access to the Microsoft Media Pack, a set of licensed media codecs for video and audio.

The Mono Project is an open-source initiative sponsored by Novell to develop a Unix version of the Microsoft .NET development framework.