Review of three products: Applied Semantics Inc.'s Auto-Categorizer 1.1, Interwoven Inc.'s MetaTagger 3.0 and Thunderstone Software LLC's Texis Categorizer 4.1.
Auto-categorizer is a hierachical categorizer which requires ontologies for specific content such as health and insurance. Metatagger is integrated into Team Site and with an extraordinary six figure price. Categorizer is much cheaper solution and provides a manual selection of concepts that are relevant to a document. It requires a size of 20 highly relevant document to use a training set.