In 2016 the National Forum for the Enhancement of Teaching and Learning in Higher Education funded three Irish academic libraries to review, implement and evaluate a new "National Professional Development Framework for All Staff who Teach in Higher Education" over two years. The Framework situates professional development as a process that starts with the 'self' in teaching and learning, but also emphasises communication and dialogue, and can be formal or informal. Its flexible, inclusive design encourages all staff who contribute to student learning to tailor it to their individual and group needs throughout their careers. The present study explains how project participants used reflective practice, action research, communities of practice, seminars and workshops to interrogate and apply the Framework, and reflects on what they learned from their experiences, and how it has influenced library practice in Ireland. Project outcomes include a website hosting reusable learning objects, an open access book evidencing reflection and scholarly communication skills, and insights into the identity of librarians as teachers and the role of personal, professional and organisational values and philosophy in professional development.