  We provide a short review of Courant algebroids and graded symplectic
manifolds and show how different Courant algebroids emerge from double field
theory. Fluxes of double field theory and their Bianchi identities are
formulated by using pre-QP-manifolds. We stress the relation of the Poisson
Courant algebroid with R-flux as a solution of the double field theory section
condition.
