WebMethods is actually a company -- that develops a messaging product. Sort of a competitor to MQ-series and Tibco. They do provide JMS (Java Messaging Service) compliant libraries. And since JMS is part of the J2EE, all compliant application servers should provide the mechanism to connect to the WebMethods service where as Web Services involves the usage of XML data standards over the HTTP protocol. It is part of the J2EE standard, so all compliant application servers should have the libraries to be able to connect (and serve) web service based applications.