Date: May. 23, 2001
Link: http://www-106.ibm.com/developerworks/library/ws-peer1.html?dwzone=components
Source Author or Organization: Graham Glass, CEO/Chief Architect, The Mind Electric, IBM developerWorks

This first in a series of columns about the challenges and benefits of building Web services begins by defining the term itself ("a collection of functions that are packaged as a single entity and published to the network for use by other programs") and pointing to example applications such as Microsoft Passport. Web services offer interoperability, including escape from the hassles of converting protocols such as Common Object Request Broker Architecture (CORBA) and Distributed Component Object Model (DCOM), thanks to Simple Object Access Protocol (SOAP). They present developers with a low barrier to entry, as well as current support from all major vendors.

XML and Hypertext Transfer Protocol (HTTP) -based communication means Web services will be ubiquitous, playing in a sandbox that's growing as fast as the proliferation of browsers and various Web-enabled devices. But Web services must survive in a demanding environment. They must make themselves discoverable by other services, a problem being addressed by Universal Description, Discovery and Integration (UDDI) and Web Services Definition Language (WSDL). They must handle secure transactions spanning hours or days in an open environment, which may be addressed by XLANG or Transaction Authority Markup Language (XAML). They must be scalable, which may be possible with existing component structures such as Enterprise Java Beans (EJB), or may require a new kind of application server specific to Web services. Unique management, accountability and quality assurance issues are also discussed.

Glass lists several properties of two existing complex systems, biological organisms and human society, that already manage similar problems and may be applicable. He ultimately sees Web services as an evolutionary step in distributed application development that will boost innovation in Peer-to-Peer (P2P) computing.