The term Language Resources (LRs) refers to sets of language data and descriptions in machine readable form, such as written or spoken corpora and lexica or domain-specific databases and dictionaries. LRs are used in many types of components, systems, and applications, such as language-enabled information and communication services, knowledge management, e-commerce, e-publishing, e-learning, e-government, etc.
Being at the same time a theoretical and a technical enterprise, the creation of a language resource always raises a number of theoretical questions as to the way primary linguistic material should be documented and represented in it. Moreover, as computational efficiency is one of the main goals of successful, large-scale LRs, the creation of LRs forces the theoretical linguist to tackle seriously the issue of how to represent complex linguistic information when collecting and storing primary data. This is especially true for those domains of linguistics in which data are not usually represented in terms of categorial membership or binary traits, such as linguistic typology and the study of second language acquisition.
The papers collected in this volume focus on the implications of language resources for linguistic theory, and, conversely, on the implications of linguistic theory for the development of language resources, with special (but not exclusive) emphasis on LRs for language typology and second language acquisition.

Andrea Sansò is Assistant Professor in General Linguistics at the University of Pavia. His current research interests concern mainly linguistic typology, computational linguistics, linguistic theory and historical linguistics. Within the framework of the FIRB Research Program on "Europa e Mediterraneo dal punto di vista linguistico" (national coordinator: Paolo Ramat), he has supervised the creation of the Pavia Typological Database, a database collecting and documenting a number of morphosyntactic phenomena in the languages of Europe and the Mediterranean.