The effort requires the cooperation of both browser makers and plug-in builders, which will need to support the new extension. No date was set for when software plug-ins would begin supporting the new API. Macromedia, for example, is committed to including it in future releases of Flash, said Jeff Whatcott, vice president of product management at the San Francisco company. He declined to provide a timeline. The API extension will help developers more easily support a range of Web browsers, he said. "Now, with these changes, we can have a consistent developer experience across all those technologies," he said.Developers still will need to create a different set of plug-in interaction scripts for IE, which uses ActiveX, than for the coalition of rival browsers, Whatcott said. Baker said Microsoft would be welcome to support the new scriptability extension for IE, though the Redmond, Wash., software maker was not invited to participate. Microsoft officials declined to comment. Microsoft IE holds a strong grasp on the browser market with a 94 percent share, according to data from analytics vendor OneStat.com. But its rivals have made some headway in gaining converts. A series of security issues dogging IE recently prompted the U.S. Computer Emergency Readiness Team to suggest the use of an alternative browser as one way to avoid potential problems. Mozilla officials said they have already noticed an increase in downloads of its Firefox browser, though Microsoft on Friday released a new patch for IE. Click here to read about how eWEEK.com Senior Editor Steven J. Vaughan-Nichols plans to steer clear of IE. Last year, Apple entered the browser market when it began shipping Safari with the Mac OS X. That move prompted Microsoft to end future development of IE for the Mac. Baker said that by working together on new functionality such as the plug-in API extension, IE rivals are making sure that the alternative browser market remains vital. "Obviously, an alternative browser is critical, and last week has shown us that there are pretty significant vulnerabilities in the dominant browser," Baker said. "In terms of plug-ins, when people go to get Mozilla or Firefox, we want them to have the best possible experience, and part of that is a richer plug-in API." Check out eWEEK.coms Developer & Web Services Center at http://developer.eweek.com for the latest news, reviews and analysis in programming environments and developer tools.