Machine readable open public data and the issue of multilingual web are open challenges promising to transform the relationship between citizens and European institutions. In this context the DALOS project aims at ensuring coherence and alignment in the legislative language, providing law-makers with knowledge management tools to improve the control over the multilingual complexity of European legislation and over the linguistic and conceptual issues involved in its transposition into national laws. This paper describes the design and implementation activities performed on the basis of a set of parallel texts in different languages on a specific legal topic. Natural language processing techniques have been applied to automatically build lexicons for each language. Lexical and conceptual multilingual alignment has been accomplished exploiting terms position in parallel documents. An ontology describing entities involved in the chosen domain has been developed in order to provide a semantic description of terms in lexicons. A modular integration of such resources, represented in RDF/OWL standard format, allowed their effective and flexible access from a legislative drafting application prototype, able to enrich legal documents with terms mark-up and semantic annotations.