KAON is an ontology management suite of tools developed at the AIFB and FZI at the University of Karlsruhe that addresses performance capabilities such as: large quantities of information, persisting ontologies and metadata, concurrent access. It consists of the following components: RDF(S)-based ontology model with some adaptations and extensions (such as transitive, symmetric and inverse properties); API for management, persistence and modularization of ontologies and metadata; support for evolution of (distributed) ontologies; query processing module for executing DL-like queries; OI-modeler - a powerful GUI application for ontology management. The persistence and inference mechanisms of KAON are based on relational databases, thus making realization of concurrency and scalability easier. Based on the KAON tool suite there are a number of tools and applications: KAON Portal - a Web-based interface for presentation of semi-automatic generation of ontology-based Web portals; OntoMat-Annotizer - a tool that allows to semantically annotate web pages, learn extraction rules from examples and apply these rules on unseen web pages. OntoMat-Annotizer creates RDF-code building on Amilcare as its core tool for learning and applying information extraction rules.