Four major software makers will launch an updated test version of a public Web services directory that lets businesses list and find online services. IBM, Microsoft, Hewlett-Packard and SAP on Monday are expected to launch the directory, which conforms to a budding specification called Universal Description, Discovery and Integration (UDDI). The new test directory is seen as a crucial step in making UDDI more widely understood and usable. The UDDI specification is the brainchild of IBM, Microsoft and Ariba and is supported by more than 220 companies, including Oracle, Intel, Sun Microsystems, Ford Motor and Nortel Networks. The directory is an online Yellow Pages that will help companies advertise their Web services and find other Web services providers so they can conduct business online. For example, Home Depot could use a UDDI-based service that finds light-switch suppliers and ranks them according to pricing and availability of products. About 7,000 businesses have registered with the UDDI directory, but because the Web services market is still emerging, only several thousand Web services have been registered, according to the project's administrators. Web services, in essence, is a new way of building business software so systems can connect the operations of many companies and partners simultaneously, allowing them to do business through any Net-connected device. "Many companies register, but there aren't many Web services," said Jack Walicki, HP's middleware chief technology officer. "We know companies are aggressively pursuing a different view of doing business based on the concept of Web services. This (project) is meant to foster experimentation." The companies launched the effort last year as part of their goal to create the underlying technology needed to further their Web services plans. UDDI allows Web services built using Microsoft's .Net tools or Sun's Sun One plan to work together despite competitive differences. Proponents see UDDI doing for Web services what search engines such as Yahoo! did for the Internet in the mid-1990s: providing a way for people to find what they need amid a vast sea of unorganised information. UDDI is among four specifications gaining importance as the concept of Web services becomes more widespread. The others are Extensible Markup Language (XML); Simple Object Access Protocol (SOAP); and Web Services Description Language (WSDL). To understand how these protocols work together, imagine an ordinary phone call. In Web services parlance, XML represents the conversation, SOAP describes the rules for how to call someone, and UDDI is the phone book. WSDL describes what the phone call is about and how you can participate. Microsoft and IBM previously created Web sites that host the directory. SAP and HP are expected to begin hosting the UDDI directory for the first time on Monday. Because all four companies' Web sites will be connected, businesses will be able to search and register with the Web directory by entering any of the sites. The public online directory, which originally launched this spring, was created by the companies using the UDDI specification. Businesses can also create private UDDI directories so they can do business with their own customers and partners. Many analysts and early Web services participants see UDDI being used in this way, at least initially. Scott Cosby, IBM's manager of Web services marketing, said the updated iteration of the Web directory features two main improvements: the ability to make more complex searches on the directory and the ability of companies to give potential customers more information about their business. Additional information businesses can give includes the specific business unit of a company or whether the company is in good standing with the Better Business Bureau, Cosby said. Walicki said the goal is to give more information, such as certifications and alliances, so potential customers can be more confident about the Web service they will purchase or subscribe to. Cosby added that the project's supporters will submit the UDDI specification to a standards organization once they create a third version of the Web directory with more improvements and features, probably later next year. More enterprise IT news in ZDNet UK's Tech Update Channel Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forum. Let the editors know what you think in the Mailroom. And read other letters.