Since the public release of its earliest version last year, Silverlight has been touted as Microsoft's Flash killer. This relatively new Web development platform aims to challenge Adobe's venerable Flash (and associated Flex development tools) in the online multimedia space.

Its first version was a little rough, experts say, but the beta of Silverlight 2 (released in March) shows that Microsoft could indeed have a shot at challenging Adobe Systems Inc.'s hugely popular Web media platform. But adoption of Silverlight by developers or end users has yet to take off. Realistically, it's going to take more than Silverlight being able to overcome, or to simply match, the technology of Flash, according to many observers.

So I consulted industry analysts and a professional Web developer familiar with both platforms for their views on what elements are affecting Silverlight's odds in the rich Internet applications (RIA) development arena as it enters its second year.

1. Microsoft's technology on the Web

First and foremost, Silverlight was devised to bring the Windows Presentation Foundation (WPF) programming model to Web applications, and with that, the large .Net developer community. Between the Adobe Flash and Microsoft offerings, "it is not a feature war; each platform can tout some advantages. [Silverlight] is mostly about bringing Microsoft's developer ecosystem to the Web," says Al Hilwa, an analyst at market research firm IDC.

"It enables Microsoft's technology stack to have a rich media story for the Web. They didn't before; they do now," says Atlanta-based Jesse Warden, who has been developing professionally in Flash since 1998. "This means they can utilize and interface with a lot of their existing technology," says Warden, who has also started working in Silverlight.

Greg DeMichillie, an analyst at Directions on Microsoft, describes Silverlight 1.0 as "a placeholder narrowly focused on video, and not a full platform. The real action begins with the second version."

Currently in beta and set for release sometime later this year, Silverlight 2 is expected to tout more of the kind of "hard-core" graphical user interface programming that Adobe's Flex platform features. It will leverage Microsoft's strongest developer technologies: Visual Studio, C#, and the .Net Framework.

"Visual Studio is 'the shiz,'" says Warden. "I wonder why Flex Builder's Eclipse plug-in doesn't have some awesome Visual Studio feature."

"Silverlight 2 feels like it's going to be a full-on contender with Flash and Flex in a short time. Then the battle will be over ubiquity, developer hearts and minds, and control of the Web," says Michael Cote, an analyst at RedMonk.

2. The enduring appeal of Flash development

Adobe is the clear leader today, but while Flash has improved technically over the years, it is still quirky from the perspective of hard-core development," says Hilwa.

But Flash continues to appeal to most Web designers and animators, despite improvements that are coming to the next version of Silverlight. "Version 1 of Silverlight was OK. Version 2 is definitely hot, especially when compared to where Flash Player 9 is at," says Warden. "Regardless, I'll currently stick to Flex and Flash. It's currently more fun, and there is more money in it."

3. Wider cross-platform support

"I'm always waiting for the .Net CLR [Common Language Runtime] to be a big deal. But without solid cross-platform support on runtime and tools, the CLR's benefits are limited to Windows developers," says Cote. "If there's a good cross-platform and even -- dare I say it? -- open-source [feature] when it comes to runtimes and tools, new developers will be interested as well."

In fact, Warden's advice for Adobe to continue to make its Flex system competitive with Silverlight coincides with Cote's view on what Microsoft should do for future iterations of Silverlight: "Keep the open-source mentality going strong, and keep up with the Linux support.

4. Interest beyond traditional developers

Warden says present demand for Silverlight development in his field is "extremely low." He describes the amount of work a busy developer can get as "one [job] a day for Flash" compared with "one every four months for Silverlight."

"Most work I'm seeing [for Silverlight] is because the company is a Microsoft partner," he says.

Regardless, the analysts see significant interest in developing on the platform, even among those who are not programmers. "Many folks I know in the design community are taking a good look at it," says Hilwa.

DeMichillie is keeping an eye on the possibility of Silverlight making inroads in the enterprise. This could be a market in which Microsoft has an advantage over Adobe.

"Silverlight is a threat to Flash and Flex for sure. For me, the really interesting competitors are companies like Google and Yahoo," said Michael Cote, analyst at RedMonk

"The interesting question is when, if ever, will corporations turn to RIA [rich Internet application] technologies for internal applications. Microsoft clearly has a stronger presence among corporate developers. At this point, RIA development is overwhelmingly aimed at public Web sites," says DeMichillie.

5. AJAX, et al

Silverlight is up against not only Flash, but also other established, and firmly entrenched, Web technologies. "Silverlight is a threat to Flash and Flex for sure. For me, the really interesting competitors are companies like Google and Yahoo who depend on the Web being primarily HTML/AJAX-based to serve up ads and provide other services," Cote says. "A new UI layer that runs on top of the Web could be a real hassle for services that are used to the more 'view source' nature of the Web."

Warden notes that a patched-together mix of Java, HTML and other technologies will pose probably the biggest challenge to Silverlight: "It'll be interesting to see if the .Net crowd does the same thing that Java guys are doing. Most .Net I see on the Web is simple HTML/CSS/JavaScript and AJAX stuff," he said, referring to Asynchronous JavaScript and XML.

6. Co-existence in the market

Because it is installed on over 90% of Internet-connected PCs, Flash will remain the default choice for most Web developers. For now.

"Flash Player is ubiquitous, and every developer takes that for granted. To win, Silverlight needs to have that perception, too," says Warden. "Users do not care what they install; they just care [that] what they are watching is relevant and cool."

He believes Microsoft is very committed to seeing Silverlight succeed, no matter what. "The amount of money, time and talent I'm seeing being thrown at it makes me fail to see how it won't succeed in some fashion," he says.

However, Microsoft will need to convince a high number of users to install Silverlight. DeMichillie estimates that as much as 80% of Internet-connected PCs must have Silverlight installed in order for the platform to hold its own, in the market and among developers, against the status quo of Flash.

"Microsoft knows this is a prerequisite, which is why they are willing to spend money to make high-profile deals, like the one with NBC for Olympics coverage," he says.

DeMichillie foresees Silverlight eventually overcoming the dominance of Flash, but adds: "The market for these platforms is in the very early stages, so it's not a zero-sum game. Even in the longer term, I think coexistence is more likely than 'winner takes all.'"

Even Warden acknowledges that his business plans to do more Silverlight work, though "I don't want to do it because it looks like early [versions of] Flash, and I'm done with that. I want more challenging Flex work instead."