In this case study we present innovative work in building open corpus-based language collections by focusing on a description of the opensource multilingual Flexible Language Acquisition (FLAX) language project, which is an ongoing example of open materials development practices for language teaching and learning. We present language-learning contexts from across formal and informal language learning in English for Academic Purposes (EAP). Our experience relates to Open Educational Resource (OER) options and Practices (OEP) which are available for developing and distributing online subject-specific language materials for uses in academic and professional settings. We are particularly concerned with closing the gap in language teacher training where competencies in materials development are still dominated by print-based proprietary course book publications. We are also concerned with the growing gap in language teaching practitioner competencies for understanding important issues of copyright and licencing that are changing rapidly in the context of digital and web literacy developments. These key issues are being largely ignored in the informal language teaching practitioner discussions and in the formal research into teaching and materials development practices.