  In this expository and resources chapter we review selected aspects of the
mathematics of dynamical systems, stability, and chaos, within a historical
framework that draws together two threads of its early development: celestial
mechanics and control theory, and focussing on qualitative theory. From this
perspective we show how concepts of stability enable us to classify dynamical
equations and their solutions and connect the key issues of nonlinearity,
bifurcation, control, and uncertainty that are common to time-dependent
problems in natural and engineered systems. We discuss stability and
bifurcations in three simple model problems, and conclude with a survey of
recent extensions of stability theory to complex networks.
