The paper deals with DEB - Dictionary Editor and Browser - a new client-server system, that allows fast development of lexical databases and general ontologies. The architecture is based on XML and related W3C standards (XSLT, XML Schema, XPath, DOM, etc.). The main feature which brings the efficiency of retrieval is the extension of a standard XSLT processor with the ability to obtain additional data from the dictionary server through the mechanism of nested queries.