Building libraries is often like piloting passenger planes. As tempting as it might be to perform some thrilling and daring acrobatic maneuver in mid-flight, there are a lot of people depending on a safe arrival who would prefer that you didn't. Writing software for general reuse requires discipline, empathy, and careful consideration of trade-offs. In this session, we'll fly along with Joel Webber and Kelly Norton as they discuss general best practices for building GWT-based libraries with an eye toward productivity, performance, usability, and security.