Charter schools--what was their original promise? They would enroll diverse groups of students. They would give teachers the room and power to innovate. They would be educational laboratories that would find new ways to reach students, and they would share those lessons with other public schools. But charter schools haven't lived up to their promise. Policymakers and charter school advocates have emphasized competition over cooperation, empowered management over teachers, and prioritized niche markets over racial and economic integration of students. Noted researchers Kahlenberg and Potter highlight a small but growing number of charter schools that are taking different approaches. These schools empower teachers, integrate students, and share lessons with other public schools. Green Dot Public Schools, a unionized charter school network of 21 schools based in California, offers a powerful example of how having strong systems for teacher voice can promote organizational strength and student success. DSST Public Schools in Denver, Colorado, use a combination of income- and geography-based lottery preferences to achieve diverse enrollment. And a variety of charter schools from across the United States are improving district schools through partnerships and collaboration.