This book constitutes the refereed proceedings of the 10th International Conference on Developments in Language Theory, DLT 2006, held in Santa Barbara, CA, June 2006. The book presents 36 revised full papers together with 4 invited papers. All important issues in language theory are addressed including grammars, acceptors and transducers for strings, trees, graphs, arrays; efficient text algorithms; algebraic theories for automata and languages; and more.