This paper presents the state-of-the-art of active vibration and shock isolation, with theoretical considerations limited, to idealized single-degree-of-freedom systems. Servocontrol systems postulated for use as active isolator mechanisms are reviewed with emphasis placed on active isolation systems that have been reduced to practical operational hardware. Performance characteristics of mechano-pneumatic and electrohydraulic isolation systems are discussed in detail and are compared to those of conventional passive isolation systems. Experimental data are presented to demonstrate performance characteristics of these active isolation systems in aerospace applications involving the protection of missile inertial guidance platforms during launch and a jet aircraft pilot during severe turbulence encounters. Optimization analysis and synthesis concepts are discussed relative to the design of active vibration and shock isolation systems.