The catalog takes up a special position in the supply of services of academic libraries, as a pivot for the intermediary between users and information professionals who carry the responsibility for building up collections. For 10 years, through a serious crisis, they’ve been seeing their patrons preferring the general or commercial search engines. The Web is more than a serious competitor today, ahead of the document information systems, and became the main access point for information retrieval. Libraries are trying to structure an information space that is temporarily or permanently inhabited by users, in which the service offering is developed, but it is still presented as a series of silos, with few opportunities of navigation between them despite considerable engineering efforts and a perspective of evolution towards discovery tools. The profession, having become aware of this deep crisis after accusing eddies caused by the breakdown of the digital switch, looking for ways to adapt and diversify its offering, streamlines the dissemination of information, and reinvents its roles, trying to take advantage of new practices of users, new expectations and new prospects. Libraries put their hope in new data models, trying to add a level of abstraction promoting links with the world of knowledge. The evolution towards the Semantic Web seems to be a valuable opportunity to enhance the collections and make them usable in another context, at the expense of significant efforts sized up by this analysis. A constructivist approach based on participant observation and data collection offers a vision of the outcome within the library community on the development of catalogs and intermediation tools, and an outlook on their issues.
