This book offers a practical survey of continuation- and bifurcation-based approaches for assessing the stability of power system voltage. Beginning with definitions based on IEEE/CIGRE voltage stability classifications, the text demonstrates the need for robust numerical techniques for addressing aspects of voltage instability. The basic concepts of bifurcation theory and continuation methods are presented in tutorial form, along with information on continuation power flow. The text includes access to web based simulation tools which users can use to simulate test systems.