Microsoft revealed on ambitious plans for the next version of its Silverlight browser plug-in technology for rich Internet applications, including faster startup times and software development improvements as well as more capabilities for running applications outside of a browser.

Dubbed Silverlight 4, a beta release of the upgrade is already available for download. A final release is due in the first half of next year. Silverlight 4 was discussed at the Microsoft Professional Developers Conference (PDC). Company officials also discussed Windows 7 and revealed the beta releases of Office 2010 and SharePoint Server 2010.

Silverlight 4 features a 30-percent faster startup time and new profiling support, said Scott Guthrie, corporate vice president of the Microsoft .Net Developer Platform. Version 4 will support the same OSes and browsers as in previous releases as well as the Google Chrome browser.

"We're improving startup by more than 30 percent for common scenarios, sometimes up to 80 percent," Gutrhie said.

HTML hosting capabilities are included in Silverlight 4. "You can actually now host HTML as a control within your applications," Guthire said. The upgrade also features other new controls and extends controls based on user requests.

With Silverlight 4 and .Net Framework, an assembly can be compiled once and run on both technologies.

Out of browser improvements for Silverlight 4 include Windows APIs and notification popup support. Trusted applications can be run outside the Silverlight 4 sandbox on Windows and Mac systems, with a user consent dialog featured.

Other capabilities in Silverlight 4 include data-binding improvements, UDP (User Datagram Protocol) and multicast support. REST enhancements are featured along with improvements pertaining to Windows Communication Foundation and rich Internet applications.

Accompanying Silverlight 4 will be design improvements in the upcoming Visual Studio 2010 software development platform release, including a full WYSIWIG design surface as well as XAML and Intellisense capabilities.

To better enable development of business applications, version 4 features support for programmatic printing, right click support, and rich text editing as well as programmatic access to the clipboard and built-in mouse wheel support for Silverlight capabilities. Custom print dialogs are enabled also.

"We're also adding features like implicit styling support so you can consistently style all the controls within your app," Guthrie said.

Silverlight 4 offers access to microphones, webcams, audio and video input and multicast streaming. Digital rights management is featured as well. Microsoft, Guthrie said, has been on "very fast release cadence" with Silverlight, offering the first three releases in the space of 22 months. Silverlight 4 continues this pattern, he said.

Installed on a reported 33 percent of interconnected devices worldwide, Silverlight is perhaps the most formidable rival to the more established Adobe Flash platform. Silverlight has been used for streaming of events such as the Winter Olympics and Sunday Night Football. "This provides one of the most immersive and engaging experiences on the web," Guthrie said.

He also showed a demonstration of Silverlight being used to read a product bar code, providing pricing information via a link to a web service. Special effects were shown with Silverlight enabling picture distortions similar to a carnival funhouse mirror.

In addition to its Silverlight efforts, Microsoft is offering its Internet Information Services (IIS) Media Services for "smooth streaming." The next version will enable streams to devices that do not support browser plugins, such as the Apple iPhone.