Performative, improvised, on the fly: live coding is about how people interact with the world and each other via code. In the last few decades, live coding has emerged as a dynamic creative practice gaining attention across cultural and technical fields--from music and the visual arts through to computer science. Live Coding: A User's Manual is the first comprehensive introduction to the practice, and a broader cultural commentary on the potential for live coding to open up deeper questions about contemporary cultural production and computational culture. This multi-authored book--by artists and musicians, software designers, and researchers--provides a practice-focused account of the origins, aspirations, and evolution of live coding, including expositions from a wide range of live coding practitioners. In a more conceptual register, the authors consider liveness, temporality, and knowledge in relation to live coding, alongside speculating on the practice's future forms.