Wmatrix is a software tool for corpus analysis and comparison. It provides a web interface to the USAS and CLAWS corpus annotation tools, and standard corpus linguistic methodologies such as frequency lists and concordances. It also extends the keywords method to key grammatical categories and key semantic domains.
M. Hearst. Proceedings of the 14th conference on Computational linguistics, 2, Seite 539--545. Stroudsburg, PA, USA, Association for Computational Linguistics, (1992)