This is a motivated presentation of recent results on tree transducers, applied to studying the general properties of formal models and for providing semantics to context-free languages. The authors consider top-down tree transducers, macro tree transducers, attributed tree transducers, and macro attributed tree transducers. A unified terminology is used to define them, and their transformational capacities are compared. This handbook on tree transducers will serve as a base for further research.

The refereed proceedings of the 7th International Conference on Developments in Language Theory, DLT 2003, held in Szeged, Hungary, in July 2003. The 27 revised full papers presented together with 7 invited papers were carefully reviewed and selected from 57 submissions. All current aspects in language theory are addressed, in particular grammars, acceptors, and transducers for strings, trees, graphs, arrays, etc; algebraic theories for automata and languages; combinatorial properties of words and languages; formal power series; decision problems; efficient algorithms for automata and languages; and relations to complexity theory and logic, picture description and analysis, DNA computing, quantum computing, cryptography, and concurrency.