  We develop a theory of Ricci flow for metrics on Courant algebroids which
unifies and extends the analytic theory of various geometric flows, yielding a
general tool for constructing solutions to supergravity equations. We prove
short time existence and uniqueness of solutions on compact manifolds, in turn
showing that the Courant isometry group is preserved by the flow. We show a
scalar curvature monotonicity formula and prove that generalized Ricci flow is
a gradient flow, extending fundamental works of Hamilton and Perelman. Using
these we show a convergence result for certain nonsingular solutions to
generalized Ricci flow.
