ONTOCHAIN with a €6 M fund marries the Semantic Web with Blockchain to deliver a novel software ecosystem for trusted, traceable and transparent ontological knowledge management. ONTOCHAIN, which is developed under the European Commissions Next Generation Internet initiative, explores and delivers novel interoperable on-chain and off-chain data, ontology, knowledge and information management methods. The ONTOCHAIN software ecosystem consists of a novel protocol suite grouped into high-level application protocols, such as data provenance, reputation models, decentralised oracles, market mechanisms, ontology representation and management, privacy aware and secure data exchange, multi-source identity verification, value sharing and incentives and similar, and core protocols that include smart contracts, authorisation, certification, event gateways, identity management and identification, secure and privacy aware decentralised storage, data semantics and semantic linking, ONTOCHAIN optimisation and similar. The NGI ONTOCHAIN software ecosystem will demonstrate its potential in high impact domains, such as eHealth, eGovernment, eEducation, eCommerce, decentralised infrastructures and similar in order to achieve trustworthy information exchange and trustworthy and transactional content handling.