This paper describes morphdb.hu, a Hungarian lexical database and morphological grammar. Morphdb.hu is the outcome of a several-year collaborative effort and represents the resource with the widest coverage and broadest range of applicability presently available for Hungarian. The grammar resource is the formalization of well-founded theoretical decisions handling inflection and productive derivation. The lexical database was created by merging three independent lexical databases, and the resulting resource was further extended.