Microsoft has quietly released Silverlight 5, the latest major version of its application framework competitor to Adobe's Flash.
Made available for download on Friday, Silverlight 5 adds GPU-based H.264 media decoding and various other features intended to improve quality and performance. The plug-in was originally supposed to come in November, but Microsoft missed the deadline.
Apart from the performance improvements, "Silverlight 5 extends the 'Trusted Application' model to the browser for the first time", the Silverlight team wrote in a blog post.
"These features, when enabled via a group policy registry key and an application certificate, mean users won't need to leave the browser to perform complex tasks such as multiple window support, full trust support in-browser including COM and file system access, in browser HTML hosting within Silverlight, and P/Invoke support for existing native code to be run directly from Silverlight," the team wrote.
To improve output quality and file size, Silverlight 5 makes use of Postscript Vector Printing. It also includes a 3D-supporting graphics stack that uses the XNA API to access the GPU for some rendering functions.
Microsoft released a beta for Silverlight 5 in April. However, the company has been more vocal about its support for the open HTML5 technology than about Silverlight, which is proprietary. Microsoft is encouraging developers to write apps for the upcoming Windows 8 platform using HTML5.
The company has repeatedly refused to talk about the future of Silverlight beyond version 5, and some observers have taken this as a worrying sign about the framework's long-term viability.