Microsoft Chairman Bill Gates tried to win over developers here Monday as he offered the first look at Longhorn, the next version of Windows. Longhorn is built around three major advances--a new graphics and presentation engine known as Avalon, a new communications architecture known as Indigo, and a new file system known as WinFS that borrows from Microsoft's relational database technology. Gates did not offer a time frame for delivery of the new operating system, but he said it still represents "years of work." Analysts have said they expect it could be 2006 before the new software is released. Instead of providing an estimate of when the final release will ship, Microsoft said only that a beta, or test version, of the software is slated for next summer. It was Longhorn's desktop that got the most thorough preview during Gates' keynote address at the company's Professional Developers Conference, taking place at the Los Angeles Convention Center. Among the features shown off were transparent windows, animated windows that pop open and a new taskbar on the righthand side of the screen that displayed a clock, buddy list, and news and other information streamed onto the desktop via an RSS feed. Using the relational database built into the file system, information can be viewed in new ways, such as in "stacks" based on a single common attribute. Although the concept is similar to that of folders, it is more ad hoc than the folder design and is meant to facilitate having one piece of information in several stacks. The graphics are powered by a new XML-based graphics and presentation engine known as Avalon that builds into the operating system and expands some of Microsoft's existing technologies like DirectX and ClearType. The graphical look of Longhorn--particularly its transparency and animated windows--are reminiscent of Apple's Mac OS X. Other features, such as the thumbnail image that pops up while users are scrolling through a long document, appear to be all-new ideas. The file system has already been well described, but Gates said it will fulfill a long-held vision of his that will pave the way for better searching as well as ways of grouping together e-mail, Web pages and documents that have previously been held in separate "silos." "That's been a holy grail for me for some time," Gates told developers Monday. More at ZDNet