The Writing Project is an incredibly powerful and engaging professional development program for teachers. A 35-year study found that the Writing Project's summer institutes and year-long programs effectively support teacher learning through peer teaching, discussions of research and literature, and opportunities for teachers to write and share their own work. While other initiatives have emerged, the Writing Project has maintained its successful core elements. It provides a model for locally and nationally organized, teacher-led professional development and leadership that is foundational for successful educational reform.