X-Media addresses the issue of knowledge management in complex distributed environments. It will study,develop and implement large scale methodologies and techniques for knowledge management able to support sharing and reuse of knowledge that is distributed in different media (images, documents and data) and repositories (data bases, knowledge bases, document repositories, etc.) or that is inaccessible for current systems, which cannot capture the knowledge implicit across media. All the developed methodologies aim at seamlessly integrating with current work practices. Usability will be a major concern together with ease of customisation for new applications. Technologies will be able to support knowledge workers in an effective way, (i) hiding the complexity of the underlying search/retrieval process, (ii) resulting in a natural access to knowledge, (iii) allowing interoperability between heterogeneous information resources and (iv) including heterogeneity of data type (data, image, texts). The expected impact on organizations is to dramatically improve access to, sharing of and use of information by humans as well as by and between machines. Expected benefits are a dramatic reduction of management costs and increasing feasibility of complex knowledge management tasks.