Kovacs formerly held the title of senior VP of markets, solutions, and products at Sybase and then, after its acquistion, at SAP. He worked previously for Adobe, IBM, and Zi Corporation.
John Lilly, Mozilla's current CEO, will step down to join venture capital firm Greylock Partners later this year.
"Gary brings a deep understanding of the mobile space and rich media from his time at Macromedia / Adobe and Sybase," said Mitchell Baker, chair of the Mozilla Foundation, in a blog post on Thursday. "Both of these areas are critical to the future of the Web.
Lilly in a blog post also stressed Kovacs's "deep background in mobile."
Mobile browsing has proven to be a difficult market for Mozilla. The organization has opted not to try to produce a mobile version of Firefox for Apple's iPhone because of Apple's iOS developer rules. And Mozilla only just released the first Firefox 4 beta for Android and Maemo devices earlier this month.
Mozilla's trouble replicating its desktop success in the mobile arena is compounded by the furious pace of desktop browser development. Since the release of Google's Chrome Web browser in September, 2008, Firefox's share of the browser market has remained more or less flat, with a market share ranging from 22 percentage to 24 percentage, according to NetApplications. Google's Chrome browser meanwhile has seen its market share climb to 8 percentage.
At the same time, Apple and Microsoft have stepped up efforts to make their Web browsers, Safari and Internet Explorer, more competitive.
And the competition is only going to increase. In the next month or two, Google is planning to introduce a new operating system, Chrome OS, based on its browser. And Google continues to be Mozilla's largest source of revenue.
With Apple, Microsoft, and Google all building their respective platforms beyond the browser to include mobile, desktop computing, and cloud services, Kovacs faces the challenge of developing a strategy that will allow Mozilla to thrive amid the Internet's giants.