Silverlight 4, the cherry on top of Microsoft’s developer cake, has been released to web. As promised previously, Silverlight 4 hit RTW on April 15th, 2010, following Visual Studio 2010 RTM and .NET Framework 4 RTM, which were delivered at the start of this week, on April 12. It took the latest iteration of the Redmond company’s alternative to Adobe Flash only five months to go from Beta to RTW, indicating the software giant’s strong focus on catalyzing the evolution of rich user experiences in the Cloud, but also on additional screens, including PC, TVs and mobile phones.

In the past half a year, Microsoft produced two major development milestones of Silverlight 4. The Beta build was delivered at the Professional Developers Conference in November 2009, and the Release Candidate (RC) was offered in mid-March 2010 at Microsoft’s MIX conference. Both Builds were developer-only releases. Of course, Silverlight 4 Build 4.0.50401.0 RTW is now ready for the general public.

At this point in time, Silverlight is installed on in excess of 60% of the world’s Internet-connected devices. This is nothing short of an impressive accomplishment for Microsoft, which released Silverlight 1 in September 2007. Of course, more than anything else, the high adoption rate speaks of Silverlight’s success in winning over developers, and of Microsoft’s evangelism efforts in this regard. Silverlight is no longer a mere contender in the RIA universe, but a heavyweight, and a technology that even developers in Flash- or Java-exclusive shops need to stop ignoring it.

Here is a list designed to highlight the main aspects of Silverlight’s evolution (from Microsoft):

“- WCF RIA Services introduces enterprise class networking and data access for building n-tier applications including transactions, paging of data, WCF and HTTP enhancements.

“- Comprehensive printing support enabling hardcopy reports and documents as well as a virtual print view, independent of screen content.

“- Localization enhancements with Bi-Directional text, Right-to-Left support and complex scripts such as Arabic, Hebrew and 31 new languages including Vietnamese and Indic support.

“- Read and write files to the user’s MyDocuments, MyMusic, MyPictures and MyVideos folder (or equivalent for non-windows platforms) for example storage of media files and taking local copies of reports.

“- COM automation enables access to devices and other system capabilities by calling into application components; for instance to access a USB security card reader.

“- Offline DRM, extending the existing Silverlight DRM powered by PlayReady technology to work offline. Protected content can be delivered with a persistent license so that users can go offline immediately and start enjoying their content.

“- Enhanced databinding support increases flexibility and productivity through data grouping/editing and string formatting within bindings.

“- Exclusive tooling support for Silverlight, new in Visual Studio 2010. Including a full editable design surface, drag & drop data-binding, automatically bound controls, datasource selection, integration with Expression Blend styling resources, Silverlight project support and full IntelliSense.”

Silverlight 4 Build 4.0.50401.0 RTW is available for download here.

Visual Studio 2010 Premium is available for download here.
Visual Studio 2010 Professional is available for download here.
Visual Studio 2010 Ultimate is available for download here.
Visual Studio Test Professional 2010 is available for download here.

.NET Framework 4 RTM is available for download here.