The literature reviewed in this document represents a collection of approximately 135 writings catalogued under the heading teacher leadership. The literature on teacher leadership describes a range of new roles which offer ways for teachers to grow as professionals and learn from one another. Some roles focus on inducting new teachers into the profession, such as mentoring or teaching in professional development schools. Other roles center on professional growth for practitioners through, for example, through participation in special-interest networks or in action research projects. Some of the new roles are formal, creating opportunities for career advancement, such as master-teacher appointments or differentiated staffing positions in career-ladder programs. Other roles, both formal and informal, provide opportunities for individual teachers to learn from one another through coaching or advising, support groups, teacher centers, or peer appraisal. The literature also includes descriptions of teachers learning from one another as they work together in groups, sometimes with a focus on instruction (curriculum development or instructional planning teams) and sometimes with a focus on school governance (school improvement teams). (LL)