EDBL (Lexical database for Basque) is the lexical basis needed for the automatic treatment of Basque. It was first developed as a lexical support for the spelling checker and corrector XUXEN, but in the course of the time it has proved to be a multipurpose tool. Nowadays, it is not only the lexical support of the speller but also of the morphological analyser MORFEUS and the lemmatiser EUSLEM. In the future, it will be also used for syntactic and semantic analysis. Being neutral in relation to linguistic formalisms, flexible, open and easy to use, EDBL is, along with corpora, an essential tool for the Natural Language Processing. It is made up of about 75,000 entries divided into dictionary entries (the same you can find in a conventional dictionary), verb forms and dependent morphemes, all of them with their respective morphological information. Currently, it is organized in a hierarchical structure, according to a category-system adapted to Basque. It aims to reflect the general lexicon of standard Basque (Euskara Batua) and it is the essential lexical information-store for Basque NLP.