MDA (Multilingual Document Authoring) is an interactive natural language generation system which uses a unification grammar formalism for the specification of well-formedness conditions both on the semantics and on the surface realization of documents. The MDA project provides interactive tools, such as context-aware menus, for assisting monolingual writers in the production of multilingual documents. The author's choices have language-independent meanings (example: choosing between a solution and an emulsion in a drug description document), which are automatically rendered in any of the languages known to the system, along with their grammatical consequences on the surrounding text. Although the author is not explicitly following standards, the text produced by the system is implicitly controlled both:

• Syntactically: the choice of the standard term for expressing a given notion is under system control, as is the choice between grammatical variants (such as active/passive sentences) for expressing a given information;
• Semantically: the consequences of a choice somewhere are reflected across the whole document, the author cannot forget to provide some information that the system requires, dependencies between semantic parameters such as gender and pregnancy can be described.