The unusual history of multimedia libraries run by works committees is linked to both the history of public libraries and the workers’ movement. Such libraries are precious resources whose main asset is their ease of access on site at the workplace. They are now facing the challenges of globalisation, the changing workplace, and developments in the cultural field; they are increasingly neglected by employees, and their very existence is being called into question. The author sets out to demonstrate that such libraries are in fact now more necessary than ever, as the possibility of lasting cultural emancipation for every employee is at stake. The article is completed by a description of two such libraries belonging to the SNCF and the RATP and an interview with the head of cultural policy at the CGT trade union.