This poster is presented at the 2026 Digital Humanities Benelux conference. It describes the FedOSC project, a two-year initiative (2024–2026) led by BELSPO and Belnet to support Open Science and FAIR data practices across Belgium’s Federal Scientific Institutes, with a particular focus on the specific needs of GLAM (Galleries, Libraries, Archives, Museums) contexts. It highlights how the project combines policy, infrastructure, and community-building efforts to improve visibility, coordination, and data management practices, while adapting Open Science approaches to the heterogeneous and context-dependent nature of cultural heritage data.