Edge of Chaos is a FAUST library dedicated to the implementation of music complex adaptive systems. Edge of Chaos is the result of the author's 15-year-long research on feedback systems and complex adaptive systems for the generation of music through recursive audio networks, particularly following an agent-based modelling approach. The library comprises a large set of functions ranging from standard DSP techniques to original algorithms. These include functions for the extraction of low-level and high- level information, the processing and generation of audio streams through dynamical systems, linear and nonlinear mapping strategies to couple information and sound, as well as energy-preserving functions to guarantee stability in self-oscillating systems. The library is available on Github and it is published under the GNU GPLv2.0license.