Despite many powerful visions of how technology can improve teaching and learning, the use of computers in schools continues to be limited. This in-depth study of a computer-using school analyzes the relationships among teachers' knowledge, their ongoing learning, school organizational culture, and policy to understand how the school developed high-quality use of computers. The author traces the experiences of five teachers in a large secondary school who have all used technology to augment core elements of their teaching, with particular attention to the use of computers for constructivist teaching.