MOST (Meaningful Open Schooling Connects Schools To Communities) supports European school students and citizens in developing science knowledge, transversal skills and competences in working scientifically. MOST enables and encourages its target groups to pursue scientific careers and long-term, will raise the numbers of scientists in Europe. To achieve this, our Consortium of 23 partners from 10 European countries (higher education institutions, schools, non-formal education providers, ministries, municipalities and enterprises) proposes a powerful Open Schooling idea. The project opens up formal science education and establishes partnerships between schools and their communities (families, science education providers, citizens, businesses, etc.) to work jointly on environmental school-community-projects (SCPs). These participatory projects directly respond to the needs and values of those involved, benefit the communities as a whole and make schools agents of community well-being. MOST’s learning impact is boosted through an educational research-based approach that raises interest in science, scientific literacy and environmental responsibility. MOST works on a threefold geographical structure: within communities (schools as hubs), at regional level in our 10 partner countries (connecting all open schooling communities from one region) and, ‘creates a bigger picture’ by establishing an Open Schooling Network at the European level. MOST fairs in each partner region maximise impact and strengthen regional efficacy. A final MOST Conference connects all SCPs across Europe to a vibrant science-learning network that opens up to further countries and communities. Planning and implementation involve all relevant actors: formal/non-formal education, research /practice, policy, innovation-driven businesses and society as both benefactor and innovation driver. This raises actors’ willingness to engage long-term and thus, helps ensure impact beyond project lifetime.