@article {106, title = {The JOpera visual composition language}, journal = {J. Vis. Lang. Comput.}, volume = {16}, year = {2005}, month = {February}, pages = {119{\textendash}152}, abstract = {Composing Web services into a coherent application can be a tedious and error-prone task when using traditional textual scripting languages or emerging XML-based approaches. As an alternative, complex interactions patterns and data exchanges between different Web services can be effectively modeled using a visual language. In this paper, we discuss the requirements of such an application scenario and we fully describe the JOpera Visual Composition Language. An extensive set of visual editing tools, a compiler and a debugger for the language have been implemented as part of the JOpera system with the goal of providing a true visual environment for Web service composition with usability features emphasizing rapid development and visual scalability. }, keywords = {data flow, JOpera, visual composition languages, Web service composition, Web services}, issn = {1045-926X}, doi = {10.1016/j.jvlc.2004.08.004}, author = {Cesare Pautasso and Gustavo Alonso} }