Since its creation in 1975, ECMWF has worked very closely with its Member and Co-operating States, as well as partners around the world to improve numerical weather prediction and related sciences. More recently, ECMWF has built a close partnership with the European Union and delivers on its behalf the Copernicus Climate Change and Atmosphere Monitoring Services, and is also part of the Destination Earth Initiative. We will mark the 50th anniversary of ECMWF in 2025 with a series of publications and events highlighting some of the key scientific achievements of ECMWF in collaboration with its Member States.