Project X, a high-power proton facility, will support world-leading programs in long-baseline neutrino physics and the physics of rare processes. It will be unique among accelerator facilities worldwide in its flexibility to support multiple physics programs at the intensity frontier. Project X is based on a 3 GeV continuous-wave superconducting H- linac. Further acceleration to 8 GeV, injected into Fermilab's existing Recycler/Main Injector complex, will support long-baseline neutrino experiments. Project X will provide 3 MW of total beam power to the 3 GeV program, simultaneously with 2 MW to a neutrino production target at 60-120 GeV. A multi-laboratory collaboration with international participation has undertaken the development of Project X.