Sun is releasing the source code for a user interface technology that provides users with a 3D view of their PC desktop, part of an effort to drive greater use of Java on PCs and other client devices.Sun\u00a0is releasing the source code for a user interface technology that provides users with a 3D view of their PC desktop, part of an effort to drive greater use of Java on PCs and other client devices."The client is back," said Jonathan Schwartz, Sun's president and COO, in a speech at the start of the JavaOne show in San Francisco Monday. He also previewed an upcoming version of Java 2 Standard Edition, the desktop version of the Java standard.Called Project Looking Glass, Sun's interface technology was first shown a year ago. It should allow developers to build desktop user interfaces that are easier and more intuitive to use than traditional desktop windows, Schwartz said.With Looking Glass, application windows are translucent and appear to hover on the screen. Users can stack, rotate and flip the windows in whichever way makes it easier to find and view information they want to use. Enamored with the technology's gee-whizz factor, Sun plans to show it off on giant screens on street corners around San Francisco this week.Looking Glass is for computers running Linux and Sun's own Solaris operating system. By offering the code under an open source license, Sun hopes to draw the attention of more developers, who it hopes will use the technology and improve it further. It plans to release a Looking Glass software developer kit in the coming months, officials here said.Looking Glass is little more than a good-looking technology at the moment, but its release to the open source community could see it used in some interesting applications that could spur its adoption, said James Governor, principal analyst with Red Monk. And because the technology is open source, developers might be able to create a version for Windows, he said.IBM Corp. and BEA Systems have also been promoting new desktop platforms recently, Governor noted -- IBM with a project based on Eclipse, and BEA with an effort called Alchemy that aims to make the Web browser more useful by adding better caching and synchronization technologies."Schwartz said the client is back, but in fact the rich client is back," Governor said. The industry seems to be recognizing that Web portals, or personalized Web sites with multiple content windows, aren't the easiest way to navigate through information, especially for consumers, he said.Schwartz also highlighted the upcoming release of a new version of the Java standard for desktop applications. J2SE Version 5 is being targeted for release on Sept. 30 and should provide better stability, performance and ease of use that the current version, a Sun engineer\u00a0at the show said. (Based on past releases it would be version 1.5, but Sun has changed its numbering scheme to remove the decimal.)J2SE 5 includes technologies for monitoring and managing the performance of Java applications, both within the JVM (Java Virtual Machine) itself and at the application level, the engineer said. A key goal is ensuring that existing Java applications run in the new J2SE environment, he said.Schwartz acknowledged that Java's performance has inhibited its success on the desktop in the past but said it is now poised for growth.Desktops aren't the only clients Sun is targeting. Schwartz also showed a Java-powered medical device that measures a wearer's pulse and displays it on a wristwatch. And he was joined on stage by the CEO\u00a0of Siemens' automotive division, who showed off a state-of-the-art BMW fitted with Java applications for navigation, entertainment and communications.Just as cellular operators provide cheap or free phones in exchange for service plans, so auto makers could offer free vehicles by selling subscriptions for things like breakdown, navigation and even entertainment services delivered to on-board video screens, Schwartz predicted. "Do you know a 17-year-old who would pay $5 to download a new horn sound?" he asked rhetorically. "I do."An auto executive recently told Schwartz that his company would need to charge $220 per month for services in order to give away a car for free, Schwartz said. General Motors' OnStar service already charges about $80 per month for its highest-end service, he noted.As in past years, Schwartz devoted much of his speech to the success Java has had in all kinds of products, ranging from servers to tiny gadgets. There are currently 350 million Java-enabled phones in the world and 600 million Java smart cards, he said, which are used by government health services, banks and the military, among others.Schwartz talked less about Java in the enterprise than in past years. But he did unveil an initiative to provide software for building a services-oriented architecture (SOA), in which applications and their component parts can be reused and linked together more easily.Called Project Kitty Hawk, it includes professional services for designing an SOA that will be available this month, as well as enhancements to Sun's Java Enterprise System and other products that will start appearing in 2005, Sun officials said.Sun comes to the SOA party later than software vendors such as IBM\u00a0and BEA Systems but may be able to distinguish its offerings by linking them to its popular directory server software, said Shawn Willett, principal analyst with Current Analysis.Schwartz said there are about four million Java developers in the world today, up from three million a year ago. The Java community is marching steadily toward its goal of 10 million, he said.