Researchers in theoretical linguistics, psycholinguistics, cognitive science, and in natural language processing have recently converged on a collective insight: formalizing the syntax of words is central to describing, understanding, and analyzing language. This insight has sparked considerable interest in Tree Adjoining Grammar, a lexically-oriented mathematical formalism that can precisely capture the syntactic properties of natural languages such as English or Korean. This volume combines contributions from a variety of authors who discuss the formalism itself, its use in analyzing linguistic phenomena, and its use in building natural language processing systems.