Web Services are self-describing, self-contained, modular applications that can be mixed and matched with other Web Services to create innovative products, processes, and value chains.
The Application Service Provision (ASP) paradigm, in which a provider makes services of a shared pool available to its customers, is the most promising approach to foster the industrial use of Web services.
This paradigm may enable not only the outsourcing of IT resources, but also of the software design and maintenance process; it guarantees the delivery of applications with minimum start-up fee and no-upfront investment. However, this technology is still at its early stage, and promises still don’t match a technological offer, in particular in the context of data-centric applications, where external services must be used in conjunction with internal or external data sources. In particular, a crucial aspect for the success of the ASP model is the development of high-level, easy-to-use, ASP-delivered design environments, by means of which companies can develop their applications efficiently and remotely, for subsequent deployment either on their own sites or in Web farms.

The aim of the WebSI Project is to introduce a combination of innovative abstractions, technical solutions, interfaces, components, and design tools to support the business sector in the building of ASP-based applications as composed Web services, thereby offering to a broad spectrum of enterprises a low entry cost technology, capable of collecting information and composing services from different sources. WebSI will therefore develop and demonstrate three suites of tools for generating data-centric Web applications in the ASP framework:

• The Web Site Design Suite will focus on tools to assemble Web applications on high-level, graphic user interfaces, thus generating personalized Web sites, and deploying them according to the ASP Model.
• The Service Composition Suite will provide composition abstractions in order to compose Web Services into more complex businesses.
• The Data Integration Suite will provide primitives for collecting and integrating data from multiple sources, and security mechanism to data control access.

The three tool suites will be usable within the ASP Infrastructure Layer, providing also the hosting of internal services and databases. Three applications will be developed to help focusing the design on real problems, to demonstrate the WebSI technology, and to ensure market needs feedback.