Dieselpoint has Search & Navigation Software and services for large-scale document management. They have a good SWF demo of how their technology can be integrated into a portal, see Portal Demo. They claim to have an innovative way of “using the attributes of a data set to build menus that allow a user to browse in an intelligent way.” (See Faceted Navigation – Guided Navigation) It looks like they license their Java code for others to integrate into other products too.