<p><span style=color: rgba(0 0 0 1)>This second Special Issue connects both the fundamental and application aspects of thermomechanical machines and processes. Among them engines have the largest place (Diesel Lenoir Brayton Stirling) even if their environmental aspects are questionable for the future. Mechanical and chemical processes as well as quantum processes that could be important in the near future are considered from a thermodynamical point of view as well as for applications and their relevance to quantum thermodynamics.</span></p><p><span style=color: rgba(0 0 0 1)>New insights are reported regarding more classical approaches:</span></p><p><span style=color: rgba(0 0 0 1)>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Finite Time Thermodynamics F.T.T.;</span></p><p><span style=color: rgba(0 0 0 1)>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Finite Speed thermodynamics F.S.T.;</span></p><p><span style=color: rgba(0 0 0 1)>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Finite Dimensions Optimal Thermodynamics F.D.O.T.</span></p><p><span style=color: rgba(0 0 0 1)>The evolution of the research resulting from this second Special Issue ranges from basic cycles to complex systems and the development of various new branches of thermodynamics.</span></p>