Sun Microsystems Inc. says its Jxta technology for peer-to-peer computing is gathering steam and may soon make its way into some of its own products

The number of developers who have downloaded the free Jxta code from the Web passed 2 million recently, up from about a million last March, said Juan Carlos Soto, director for advanced technologies at Sun. The number of developers who have registered at www.jxta.org is much lower, however, at about 16,200, up from 12,000 a year ago. A key goal at Sun has been to make Jxta better suited for use in commercial applications. In December it released version 2.2 of the J2SE (Java 2, Standard Edition) implementation of Jxta, an upgrade which focused on improving security and performance. A further release, with the code name Churrasco, is due in March. Unveiled almost three years ago by Sun's then chief scientist, Bill Joy, Jxta provides a communications mechanism for linking peers -- such as a PC, server, phone or PDA -- in a distributed network. Such peer-to-peer networks typically aren't run by a central server, and Jxta provides a way for the peers to locate and communicate with each other directly. It is offered under an open source license, which means developers can tinker with the code. It is also free, making it attractive to some. But the fact that it is free has also been a source of criticism. Some analysts have wondered what Sun gets in return for its investment in developing Jxta, and why it hasn't made use of the technology itself.