This proceedings volume edited by Tino and Kasevich offers a review of current activities, issues, and prospects in the field of atom interferometry as presented at the 2013 Varenna School. Several long, detailed papers are presented, covering a general review of atom interferometry, interferometry with composite quantum objects, use of internal excitation, general relativity and gravitational waves, quantum mechanics and matter waves oscillating at the Compton frequency, Bloch oscillations, precision measurement of the gravitational constant, inertial sensing, measurement of local gravity, several contributions on gravitational wave detection, measurement of electromagnetic interactions, Bose-Einstein condensates, phase estimation, and interferometry beyond classical limits. Annotation ©2015 Ringgold, Inc., Portland, OR (protoview.com)