This monograph presents our recent results on the proportional-integr- derivative (PID) controller and its design, analysis, and synthesis. The fo cus is on linear time-invariant plants that may contain a time delay in the feedback loop. This setting captures many real-world practical and in dustrial situations. The results given here include and complement those published in Structure and Synthesis of PID Controllers by Datta, Ho, and Bhattacharyya 10]. In 10] we mainly dealt with the delay-free case. The main contribution described here is the efficient computation of the entire set of...