While observers believe that Microsoft is willing to pay Yahoo US$44 billion primarily for its users and advertising base, Microsoft's chief software architect, Ray Ozzie, wants to grow its developer community as well.

"We respect the work Yahoo has done in the realm of creating an open development platform through its Yahoo Developer network and look forward to extending this great work to an even broader base of developers," he said during a press conference discussing Microsoft's offer on Friday.

The question now is how that process would unfold. Yahoo's approach to development has indeed emphasized open source. In contrast, Microsoft has a deep investment in its proprietary .NET programming framework and Visual Studio IDE (integrated development environment). It only recently began making some overtures to the open-source community.

But Microsoft also boasts a vast army of loyal developers -- something that Yahoo can't necessarily claim, although it does maintain the Yahoo Developer Network. And a Yahoo purchase clearly ties into its emerging "software-plus-services" strategy for distributing online applications.

This may be a case where the pieces fit to form a serendipitous whole, according to one observer.

"Yahoo has the most beautiful set of [application programming interfaces] in its properties," such as for the Flickr photo-sharing site, said James Governor, an analyst with Redmonk. "But frankly, it just has not done a great job of building an ecosystem. ... There's no such thing as a 'Yahoo developer.'"

Yahoo's tools hold promise, but really need a high-profile evangelist pushing hard behind them, Governor argued. "The first thing I would do in taking over the company would be to get someone who really understands APIs ... to me, Jon Udell -- who is now at Microsoft -- would be ideal in this role. He would be someone I would be thinking of right away," he said.

While Yahoo's APIs arguably are more consumer-oriented, they could still hold value within the average corporate shop, Governor said. "There's no reason why Flickr can't have some enterprise applicability. ... For the enterprise developer it's probably not the biggest thing in the world, but it definitely offers some cool new things."

But other observers said there are obstacles as well as opportunities.

John Gruber, who writes about the Web and Apple at his site, daringfireball.net, sees a major architectural clash between Microsoft and Yahoo, which has an infrastructure that incorporates Linux.