Markets are the basic mechanism by which resources are allocated to agents. In recent years, computer scientists and economists have re-engineered markets with a particular eye towards efficiency (i.e., that the market optimizes the designer's objective) and stability (i.e., that the market operates in the presence of strategic agents). Examples include diverse settings with their own peculiarities, such as organ donation, school choice programs, course allocation, medical labor markets, and the matching of cadets to army positions.