This demo from Semantic Research features natural language knowledge extraction and semantic modeling of documents, visual navigation of concepts and relationships across semantic networks, and question answering.  

First, the  software is used to index the Semantic Wave 2008 Report. This results in an executable semantic network of the knowledge contained in the report, which can be further trained, queried, and analyzed interactively. The semantic graph is presented and navigated visually in diagrammatic form. Also, it can be queried with answers and reasoning paths depicted and/or described in natural language with explanations.