The paper outlines briefly the theoretical background to the TDC design procedure, which is based on new methods of input-output state variable feedback control which exploit a non-minimum state space formulation of the control problem using either pole-assignment or linear quadratic optimal control strategies. It then goes on to describe the main features of the computer aided control system design package, which provides the user with assistance at all stages in the design process; from model identification and estimation to final control system design and evaluation, including a rather novel use of Monte Carlo analysis to assess the potential effects of model uncertainty on the closed loop system behaviour.