It is our great pleasure to put up this special issue in Joal of Control Theory and Applications in honor of the 60th birthday of Professor Frank Lewis, who has made many significant contributions to the field of control engineering through the years, and who is regarded as a pioneer in many areas in control and automation, which includes applied optimal control and geometric systems theory in his earlier research period, and his recent focus on intelligent nonlinear control, neural network feedback control, optimal control for nonlinear systems, H-infinity (game theory) control, approximate dynamic programming, discrete event supervisory control, intelligent diagnostics and prognostics, to name a few.