BANGALORE, INDIA: After an extended public beta, Microsoft has gone live with Silverlight 2.0, its rich cross-browser framework that provides a subset of Windows Presentation Foundation (WPF) controls.

It's the first "serious" version of the framework, providing a critical mass of visual controls, programmatic features, and high-bandwidth video performance capabilities to stoke enterprise developer interest.

But it won't be a game changer. Silverlight makes the RIA world safe for .NET developers, but it won't help Microsoft attract designers defecting from Adobe's base. It might eventually give Microsoft an RIA toehold in mobile, but a compact version of Silverlight isn't even ready yet.

For enterprise developers, Silverlight 2.0 makes it safe to venture beyond Ajax

Silverlight 2.0 is Microsoft's first definitive cross-browser response to Adobe's Flash-based Flex RIA platform.

The beta survived its Beijing Olympic Games face-off with Adobe. Silverlight was used by NBC.com for streaming to the US while Adobe Flex was used by China's CCTV.com for home-country viewers. With that battle under its belt, Silverlight is now ready for prime time.

Silverlight 2.0 adds enough visual controls and changeable skins to make RIA developers dangerous. It adds programmatic support that enterprise developers expect, including support of a subset of the .NET Framework, plus the ability to call network services, such as SOAP, REST, HTTP, and Plain Old XML (POX). It also adds productivity features, such as templating, so developers or designers do not have to manually cut and paste copies of controls if they want a consistent look and feel across different web pages or parts of a web page. And there is the high-definition video support that was battle-tested with 70 million streams during the 2008 Olympic Games.

While Silverlight is supposed to be a subset of WPF, there remains some unfinished business. For instance, Silverlight 2.0 has a rudimentary visual state control that provides a lightweight event-based trigger that could change the appearance of a control. That would be useful for user navigation, where a user clicks a button, or a dashboard, when data for a particular variable passes a specific threshold and turns a button from red to green. However, the capability has yet to be developed for WPF, which will eventually support more sophisticated event-triggering logic.

Microsoft developed Silverlight because it realized that it couldn't win the RIA platform war on Internet Explorer (IE) alone. Out of the box, Silverlight 2.0 runs on the Mac; supports Firefox and Safari in addition to IE; and supports non-.NET scripting languages – although in the case of Python and Ruby, support is for the Windows-optimized "Iron" dialects of those languages. And Microsoft is continuing to use open source as the latter-day sequel to its classic "embrace and extend" strategy by:

* cooperating with the Mono Project, which is developing cross-platform Silverlight tooling
* sponsoring French ISV Soyatec's Silverlight plug-in project for Eclipse to reach Java developers
* exposing the XAML vocabulary and Silverlight Control Pack under open-source-like arrangements from Microsoft's own Codeplex portal to encourage ISVs to OEM Silverlight support.

Silverlight 2.0 is not a game changer. Robust enough to keep Microsoft's .NET developer base in the fold, it still lacks the rich visuals of the Flash runtime (on which the Flex framework and AIR runtime are based). For instance, the Flash runtime has long supported vivid 3D, but Silverlight does not. Silverlight won't poach designers from Adobe's base anytime soon.

The mobile fight waits for another day

Microsoft claims to have Silverlight on a quarter of all consumer machines; that compares to about 98 percent for Adobe. However, that doesn't count mobile, where Adobe is a step ahead with Flash Lite and claims about 10 percent of the smartphone market. As for Microsoft, it starts with barely a couple of percentage points of Windows Mobile penetration and mobile Silverlight must wait for an upcoming dot release.

Either way, Adobe and Microsoft are likely to be bit players in the mobile space during the foreseeable future. They are contending over a highly fragmented iPhone aspirational market, as the iPhone itself remains out of reach.

(Author is senior analyst at Ovum)