This workshop, sponsored by AIM and the NSF, will focus on various aspects of functoriality and automorphic L-functions, with an emphasis on Langlands' proposal "Beyond endoscopy". The proof of the fundamental lemma (notably by Ngo Bao Chau, building on work of many others), and its variants, leading to the stabilization of the trace formula by Arthur, has been fruitfully applied to obtain functoriality between classical groups and GL(N). As these so-called endoscopic types of functoriality are just a small fraction of general functoriality, this naturally leads to the question of strategies and tools that may be used to attack more general cases of functoriality. Recent papers of Langlands, Arthur, Ngo and others put forth the trace formula and generalizations of Poisson summation formula as prominent tools.