Keeping the pressure on Microsoft, Sun Microsystems on Monday shipped version 6.0 of its Sun One Identity Server, the first identity server to add support for the Liberty Alliance specification that authenticates users to multiple Web sites and applications with a single user name and password.

The Liberty Alliance Project, a competitor to Microsoft's Passport authentication technology, is composed of more than 150 companies, including American Express, AOL, Hewlett-Packard, MasterCard, and Visa. Liberty released its first specs for its single sign-on standard in July and updated it in November.

Based on Security Assertion Markup Language, the standard lets users log on just once and be authenticated by all sites, applications, and Web services using the technology. Sun is a founding member of the project.

The single sign-on feature will be used initially by customers trying to consolidate identity authentication within a company, often because mergers or belt-tightening have created disparate IT infrastructures that need a return to sanity, says John Barco, the senior product marketing manager for Sun One. "Once they know they can solve this internal [authentication] issue, they'll look at how to implement this outside the company with partners," he says.

Identity Server 6.0 applies the specifications of the Liberty 1.0 standard. The most recent version, 1.1, will be supported in a service pack that Barco expects will be available in the next two months.

Out of the box, Identity Server provides a Web access manager, an identity manager to centralize management of IDs and policies, the single sign-on features, and delegated administration tools so departments can off-load identification chores from time-pressed IT staffs.

"This is the first identity server to incorporate all these functions," Barco says. "Customers who are deploying this are trying to create some efficiencies and increase security at the same time. Enforcing access is job No. 1 in most IT staffs."

Sun One Identity Server 6.0 runs with a variety of Web, directory, and application servers, including Sun's own One Directory Server and One Meta-Directory Server. For now, it works only in Solaris and Windows 2000 environments, but a port to Linux will ship in the next two quarters, Barco says. Linux candidates include Red Hat Inc.'s 7.2 and Sun's Linux 5.0.

Sun launched Identity Server in September 2001 and helped found the Liberty Alliance Project in part as a response to Microsoft's Passport authentication service. Since then, Liberty Alliance and Microsoft have taken some kiss-and-make-up steps. A spokesperson for the Liberty Alliance Project, for instance, says the next iteration of its specs would take into account any standards that come out of Oasis, the standard-setting body to which Microsoft submitted its own Web Services Enhancements 1.0 specs in June.

"But we'll only support [standards] that are going to be ratified and released," Barco says, not the plethora of security and authentication specifications just now getting off the ground.

Identity Server 6.0 is priced by the user, starting at $10 per user and falling in volume. It's available immediately, and a demo version can be downloaded from Sun's Web site.