We gathered a handful of network partners and teachers for a meeting at the Bill & Melinda Gates Foundation in Spring 2015. Participants were provided with one-page overviews of each network in attendance. Over the course of the day, we noticed teachers pouring over them and asking us, and one another, “How did I not know about this terrific resource?” Their response prompted this catalogue. The foundation partners with many dynamic organizations that network teachers to learn, connect, and lead. And we think you should know about them so that you can connect with their amazing work.