This talk aims to explain our recent construction of D=10 N=2 supersymmetric double field theory with 32 supersymmetries to the full order in fermions. The constructed action unifies type IIA and IIB supergravities in a manifestly covariant manner, with respect to O(10,10) T-duality and a pair of local Lorentz groups, or Spin(1,9) ╲times Spin(9,1), besides the usual general covariance of supergravities. While the theory is unique, the solutions are twofold. Type IIA and IIB supergravities are identified as two different types of solutions rather than two different theories. We also discuss `gauging' the doubled spacetime coordinates. Refs: arXiv:1210.5078(full N=2) arXiv:1206.3478 (bosonic N=2).