Microsoft's Windows platform is losing traction as a target for application developers in North America but still is the dominant platform, according to Evans Data survey results being released on Tuesday.

A survey this spring of more than 400 developers and IT managers in North America found that the number of developers targeting Windows for their applications declined 12 percent from a year ago. Just 64.8 percent targeted the platform as opposed to 74 percent in 2006.

"We attribute [the decline] largely to the increase in developers beginning to target Linux and different Linux [distributions]. Both Novell and Red Hat are the two dominant ones right now," said John Andrews, the CEO of Evans Data.

The arrival of Windows Vista likely only kept the numbers from being even worse. "I think Vista probably offset some of the decline," Andrews said.

The share for Windows is expected to drop another 2 percent, to about 63 percent, in the next year, Andrews said.

The targeting of Linux by developers increased by 34 percent to 11.8 percent. It had been 8.8 a year ago, according to the survey. Linux targeting is expected to reach 16 percent over the next year.

Evans views the situation as a battle of Windows versus open source with open source maturing, Andrews said. Windows remains tops, though. "They're still dominant, there's no doubt about it," said Andrews. Use of Windows on the development desktop remains steady.

The survey, featuring developers at enterprises and solution providers like system integrators, covered both client and server application development.

Evans Data said the shift away from Windows began about two years ago and is accelerating. Linux is benefiting as are nontraditional client devices. Evans Data also surveyed developer plans for such platforms as Unix and Mac OS but did not release those numbers.

A Microsoft representative said Monday no one was available from the company to comment on the Evans Data report.

Andrews said the verdict still is out on the full impact that open-source software is having on the commercial software market but noted that there will always be a place for both paradigms.

In other findings in the Evans Data Spring North American Development survey, Evans found that JavaScript is the most widely used scripting language. It has more than three times the users of PHP (Hypertext Preprocessor), Ruby, or Python. But Ruby usage is expected to increase by 50 percent within the coming year.

Also gathering steam is virtualization. A third of developers surveyed are writing applications that support virtualization with 42.5 percent expected to adopt it within the next year.