Free Web Services Resource Sites

MSDN Web Services Developer Center

Microsoft's web services resource site.

Web Sevices Mall

Web Sevices Mall presents information and resources on Web Services and related technologies like XML, SOAP, WSDL, UDDI, .Net Framework and J2EE.

developerWorks : Web services

This is IBM's resource center for web services technology. The site features tutorials, articles and many other web services resources, some of which may require registration (pretty sure it's free though).

Oracle Web Services Technology Center

Oracle's resource site for web services.

Web Services Tutorial: Understanding XML and XML Schema

This Web Service article series covers all the important standards in the Web Services stack and ties them together with real-world examples. The first article in this series discusses XML (Extended Markup Language).

Web Services with NuSOAP

This article is intended for the experienced PHP programmer, who is interested in developing web service with SOAP using a PHP-based toolkit.