The future of the SemanticWeb depends on whether or not we succeed to integrate reliably thousands of online applications,
services, and databases. These systems are tied together using mediators, mappings, database views, and transformation scripts.
Model-management aims at reducing the amount of programming needed for the development of such integrated applications.We
present a first complete prototype of a generic model-management system, in which high-level operators are used to manipulate
models and mappings between models. We define the key operators and conceptual structures and describe their use and
implementation.We examine the solutions for three model-management tasks: change propagation, viewreuse, and reintegration.