Mozilla has fixed bugs and the JavaScript engine in Firefox 3.5 and has deemed the browser stable enough for daily use Rather than offering a release candidate as had been expected, Mozilla this week released a preview of its upcoming Firefox 3.5 browser, adding fixes to bugs and the browser’s JavaScript engine as well as improvements for video and audio playback.Firefox 3.5 Preview will be offered to the 800,000-plus users of FireFox 3.5 Beta, with Mozilla looking for developer testing and community feedback. Although not a release candidate, the preview is considered stable enough for daily browsing use, Mozilla said. Testing has not been completed to the point where the software could be declared a release candidate.But a release candidate is due soon, with general availability expected later this summer. Previously, the company had anticipated a release candidate for the first week of June and general availability later this month. A Mozilla representative said the company is driven by quality rather than a timeline. Firefox 3.5 features such highlights as video capabilities and support for private browsing, in which Web site visits are not recorded or saved to disk, said Vlad Vukicevic, tech lead for the Firefox project at Mozilla. But speed improvements are paramount, he stressed.“The main significance [of the browser upgrade] is that Firefox 3.5 is really, really fast,” Vukicevic said.JavaScript performance is boosted via the TraceMonkey JavaScript engine. Other features of Firefox 3.5 include HTML 5-based capabilities for audio and video, offline caching, and the HTML drag-and-drop API for moving items within and between Web sites. CSS enhancements, including downloadable fonts, also are featured.The preview offers video and audio capabilities based on the Ogg format. Technology Industry