Explore the intricacies of library development and evolution in this comprehensive ACCU 2019 conference talk. Delve into essential aspects of creating and maintaining a successful library, including code quality, portability, testing strategies, and documentation best practices. Learn about release management, static and dynamic analysis techniques, and the importance of fuzzing. Gain insights on effectively managing library changes and leveraging tools to enhance development processes. Drawing from real-world examples from Boost and libc++, the C++ standard library implementation for LLVM, discover practical approaches to attract and retain library users. Benefit from the expertise of Marshall Clow, a seasoned programmer with 35 years of experience, author of Boost.Algorithm, and chairman of the Library working group of the C++ standard committee.