Quantum ESPRESSO is an integrated suite of Open-Source computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials. Quantum ESPRESSO has evolved into a distribution of independent and inter-operable codes in the spirit of an open-source project. The QuantumESPRESSO distribution consists of a “historical” core set of packages and a set of plug-ins that perform more advanced tasks. Researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes. Quantum ESPRESSO is an initiative of the DEMOCRITOS National Simulation Center(Trieste) and SISSA (Trieste), in collaboration with CINECA National Supercomputing Center, the Ecole Polytechnique Fédérale de Lausanne, Université Pierre et Marie Curie, Princeton University, and Oxford University. Courses on modern electronic-structure theory with hands-on tutorials on the Quantum ESPRESSO codes are offered on a regular basis in collaboration with the Abdus Salam International Centre for Theoretical Physics in Trieste.