  In the context of quantum field theory, an anomaly exists when a theory has a
classical symmetry which is not a symmetry of the quantum theory. This short
exposition aims at introducing a new point of view, which is that the proper
setting for anomaly calculations is the `in-in', or closed-time path
formulation of quantum field theory. There are also some new results for
anomalies in the context of boundary value problems, and a new correction to
the $a_5$ heat-kernel coefficient.
