DIDO: A MATLAB application package for solving optimal control problems. DIDO optimal control software is powered by pseudospectral technology and is the minimalist’s approach to solving optimal control problems. Only the problem formulation is required to use DIDO. Absolutely no knowledge of the underlying pseudospectral theory is needed to generate and validate optimal control results. Other than the optimal states, control, and time, DIDO automatically outputs the Hamiltonian, costates, path covectors, and endpoint covectors. This information can be used alongside classical tools such as Pontryagin’s principle to instantly verify numerical results.