- Web services is distributed computing technology that provides software services over the Web. The Cyberinfrastructure Group at the Virginia Bioinformatics Institute (VBI) has adopted the Web service architecture and wrapped a wide variety of bioinformatics applications and data resources using the technology. Users can browse various data resources and invoke analysis tools through the services deployed at VBI. We have also developed an integrated client environment, ToolBus, which is available from http://pathport.vbi.vt.edu/download. A use case is given to demonstrate the use of Web services through ToolBus. A complete list of Web services is included. Key words: Bioinformatics, ToolBus, Web services