This article offers a general overview on the structural evolutions of documentation for research in France. The CADIST system born in the 1980s, made of selected reference libraries designed as documentation repositories in each discipline, was replaced in 2017 by a distributed infrastructure named CollEx-Persée, destined to operate as a network steered by major heritage and research libraries as well as operators for documentation and research. After a few years of transition, CollEx-Persée is now fully in motion, according to several key issues setteled on its 2018 roadmap, introducing a new conception of what a collection of excellence should be: research-oriented, with easy access to the material on the national scale and high quality associated services for researchers. All of these aspects will be highlighed by a cross-cartography of collections of excellence and research units.