The EU IST integrated project Semantic Knowledge Technologies (SEKT) developed and exploited semantic knowledge technologies. Core to the SEKT project has been the creation of synergies by combining the three core research areas ontology management, machine learning and natural language processing.
The PROTON Knowledge Management ontology is the new, fourth module, already part of PROTON. This ontology module is actually the SEKT-specific domain ontology (former SKULO - SEKT Knowledge Management Upper Level Ontology), that has been integrated in PROTON for easier management and consistency. It is only dependent on the System and Top modules and not on the Upper module. The namespaces of PROTON are different, as shown below (check the old ones here).