1. A method of developing natural language understanding (NLU) applications comprising: determining NLU interpretation information from an NLU training corpus of text using a multi-pass processing technique, wherein alteration of one pass automatically alters an input for a subsequent pass, said NLU interpretation information specifying an interpretation of at least part of said NLU training corpus of text; storing said NLU interpretation information in a database; and in a graphical editor, presenting selected items of NLU interpretation information and receiving user specified edits to said NLU interpretation information.