The Web is a media of primary interest for companies who change their organization to place it at the core of their operation. It is an easy but boring task to list areas where the Web can be usefully leveraged to improve the functionalities of existing systems. One can cite in particular B2B and B2C (business to business or business to customer) applications, G2B and G2C (government to business or government to customer) applications or digital libraries. Such applications typically require some form of typing to represent data because they consist of programs that deal with HTML text with difficulties. Exchange and exploitation of business information call as well for a more powerful Web data management approach.

This motivated the introduction of a semistructured data model, namely XML, that is well suited both for humans and machines. XML describes content and promotes machine-to-machine communication and data exchange. The design of XML relies on two major goals. First it is designed as a generic data format, apt to be specialized for a wide range of data usages. In the XML world for instance, XHTML is seen as a specialized XML dialect for data presentation by Web browsers. Second XML “documents” are meant to be easily and safely transmitted on the Internet, by including in particular a self-description of their encoding and content.

XML is the language of choice for a generic, scalable, and expressive management of Web data.