We live in the twenty-first century. Almost all the changes between phases of matter are described by the theory of phase transitions. Yet, there is one phenomenon that still resists theoretical attempts at its description: the glass transition. Moreover, signatures of the glass transition seem to be modified in thin polymer films. These observations may provide insights into the detailed mechanisms of the transition and guide the use of thin films through promising applications. It thus appears crucial to understand the effects of confinement and interfaces on the glass transition.