The establishment of the European Science Foundation (ESF) in Strasbourg in 1974 was one of the earliest milestones on the road to achieving real cooperation in European research. The ESF began life with a membership of 42 academies and research councils in 15 countries; in 2011 it counts 78 Member Organisations (MOs), including research funding organisations, research performing organisations, academies and learned societies, in 30 countries. As an independent, non-governmental organisation dedicated to pan-European scientific networking and collaboration, the ESF has had a key role to play in mediating between a multitude of heterogeneous research cultures and agencies. The ESF hosts an array of instruments to accommodate various types and levels of international collaboration, within Europe and beyond. The ESF’s unique characteristic in this area is its responsiveness to the scientific community, in contrast with the more targeted approaches taken by the European Commission. Many of the instruments operated by the ESF, e.g. Exploratory Workshops, EUROCORES (European Collaborative Research scheme), Research Networking Programmes (RNPs) and ESF Research Conferences, are designed to respond to needs articulated by the research community. Open calls for proposals are published on an annual basis, so that the themes for programmes, networks and workshops are gathered from the research community, in line with the ESF’s bottom-up principles. This is particularly welcome in research areas which might not otherwise be prioritised for funding on an international level. In recent years, the ESF’s profile has shifted from being mainly a facilitator of collaborative research and networking to also providing a platform for Member Organisations to develop joint strategic operations and synergy among themselves. By influencing the strategic agendas of MOs in this way, greater leverage over a much larger European budget and agenda is achieved. Each year, the European Science Foundation (ESF) announces a series of calls for proposals which will give the opportunity to propose collaborative research projects and networking activities with a European dimension. The calls span all fields of science through four main funding instruments, covering all types of scientific activities, from basic research and frontier science to networking and dissemination.