We focus on the problem of data transformations, i.e., how to transform data to another structure to adapt it to new application requirements or given environments. Here, we define data transformation as the process of taking as input two schemas A and B and an instance of A, and producing an instance of B. Today, data transformations are required in many situations: to integrate multiple information sources, to construct and receive data for Web services, and to migrate data from legacy systems to new systems, from local databases to data warehouses. This demonstration focuses on XML transformations, since XML is the de facto standard for data exchange.