Society demands more of its schools and teachers than ever before. It expects them to provide broader access to high quality teaching, for an increasingly diverse student body, often with specific needs. In a rapidly-changing world, so do these demands on teachers change. To stay ahead, in-service training and professional development must take place on a regular basis, so that teachers are "reflective practitioners" in their classrooms and schools become "learning organisations". This publication focuses on what is being done in teacher development to meet these ideals -- new policies and innovative practices -- in eight OECD countries: Germany, Ireland, Japan, Luxembourg, Sweden, Switzerland, the United Kingdom (England and Wales), and the United States.