1. A data processing system for processing document data, comprising: data storage for storing a collection of document data that comprises unstructured document data; and at least one text analysis engine that comprises a plurality of coupled annotators at least some of which are operable for tokenizing document data for identifying and annotating a particular type of semantic content; where said at least one text analysis engine operates to generate a plurality of views of a document, each of said plurality of views being derived from a different tokenization of the document.