"Due to new language policies, new forms of mobility, new media and technologies, new methods of research, new dangers to minority languages, and new forms of globalization, the linguistic landscape in Europe is experiencing a profound transformation. There is a wealth of research on the teaching and use of major European languages as vehicular languages, and abundant information on the use of minority and heritage languages in Europe. However, as a basis for coherent language policy-making in Europe, we still need a systematic way to describe and measure the balance between different European languages and the impact of this balance on linguistic and cultural diversity. The project ELDIA (European Linguistic Diversity for All) combines linguistic, sociological, legal, and statistical experts from seven European countries into a consortium committed to investigating multilingualism and linguistic diversity. The research will be based on societal context analyses and fieldwork among both majority and minority speakers from samples of carefully selected multilingual speaker communities along the main cultural watershed of Europe, on both sides of the great East-West frontier and in different socio-political contexts. The central aim of the project is to create an easily applicable measurement instrument, the European Language Vitality Barometer (EuLaViBar), which can be used for the investigation of further language situations within and outside Europe. The project will also create a novel dataset for future research and will substantially contribute to the international networking of early-career researchers. Above all, by departing from the reality of multilingualism and focusing on multicultural identities and the agency of individual speakers, the project will contribute to the practical and scholarly understanding of the mechanisms of language diversity in an unprecedented way."