Content and Language Integrated Learning has received a strong tailwind in European educational and language policies. It is on the verge of becoming a mainstream phenomenon. However, an overly speedy implementation of "CLIL for all" might bear a number of risks for all groups of stakeholders. The purpose of this book is to link the growing empirical knowledge about the full complexity of CLIL to the current European educational and language policies. The articles collected in this volume contribute to a more systematic evidence base of CLIL that has frequently been called for at a European level. This bi-lingual volume (English/German) brings together authors from several European countries to present significant findings from recent CLIL research in the light of the developments in education policy. The four parts of the book focus on the reconstruction of learning processes, learner achievement, theory-driven investigations of the concept of CLIL itself, and critical reflections on the current "CLIL boom". Articles include: (1) CLIL: Complementing or Compromising Foreign Language Teaching? Effects and Perspectives of Education Policy Plans (Stephan Breidbach and Britta Viebrock); (2) Integrating CLIL with Other Mainstream Discourses (Peeter Mehisto); (3) "Mehrsprachigkeit" und "CLIL"--zwei unverbundene Konzepte in der europäischen Sprachen-und Bildungspolitik? (Bettina Deutsch); (4) Bilingual, offen, konzeptlos - Was Schulen mit reformpädagogischen Bildungskonzepten zum fremdsprachlichen Lernen versprechen und nicht halten (Henriette Dausend, Daniela Elsner, and Jörg-U. Keßler); (5) Transnationalism in Education: CLIL Experience in Turkey (Özlem Etus); (6) The Construction of the CLIL Subject Teacher Identity (Lauretta D'Angelo); (7) "Dealing with the Language Aspect? Personally, No." Content Lecturers' Views in an ICLHE Context (Francesca Costa); (8) Der Einfluss subjektiver Sprachlerntheorien auf den Erfolg der Implementierung von CLIL-Programmen (Julia Hüttner and Christiane Dalton-Puffer); (9) CLIL-Teacher Training at the University Level: Bridging the Gap between Theory and Practice (Petra Burmeister, Michael Ewig, Evelyn Frey, and Marisa Rimmele); (10) The CLIL Learning Experience: Strategies and Underlying Knowledge Employed by Limited English Primary School Students during Conceptual and Linguistic Comprehension (Irina Adriana Hawker); (11) Students' General English Proficiency Prior to CLIL: Empirical Evidence for Substantial Differences between Prospective CLIL and Non-CLIL Students in Germany (Dominik Rumlich); (12) Sprachlernprozesse im bilingualen Geschichtsunterricht (Ulrich Wannagat); (13) CLIL as a New Momentum for Learning? Reconsidering the Differences between Languages as Subjects and Vehicular Languages in Luxembourg Schools? (Marie-Anne Hansen-Pauly); (14) Deutsch als Fremdsprache fördern-ein Fall für CLIL? Sichtung empirischer Befunde in Belgien und Frankreich zu Einstellungen und Sprachlernmotivation im Zusammenhang mit "Content and Language Integrated Learning" (Katja Lochtmann and Vinciane Devaux); (15) CLIL Modules in the Mathematics Classroom--Reasons for Their Implementation and First Empirical Results--Andreas Bonnet/Christiane Dalton-Puffer: Great Expectations? Competence and Standard Related Questions Concerning CLIL Moving into the Mainstream (Katharina Prüfer); (16) It's Not CLIL That Is a Success--CLIL Students Are! Some Critical Remarks on the Current CLIL Boom (Almut Küppers and Matthias Trautmann); (17) Bili für alle? Ergebnisse und Perspektiven aus einem Forschungsprojekt zur Einführung bilingualer Module in einer Hauptschule (Götz Schwab); and (18) Generalisierbare sprachlich-diskursive Kompetenzen im bilingualen Unterricht (und darüber hinaus) (Wolfgang Zydatiß).