Introduction and Overview: Motivation Contribution Overview. - Foundations: Ontology Ontology Alignment Further Terms Ontology Similarity Use Cases Requirements. - Related Work: Theory of Alignment Existing Alignment Approaches. - Alignment Process: General Ontology Alignment Process Alignment Approach Process for Related Approaches Evaluation. - Advanced Novel Methods: Efficiency Machine Learning Active Alignment Adaptive Alignment Integrated Approach. - Tools and Applications: Basic Infrastructure Ontology Mapping Based on Axioms Ontology Engineering Platform Semantic Web and Peer-to-Peer (SWAP) Semantically Enabled Knowledge Technologies (SEKT). - Next Steps: Generalization Complex Alignments Completeness of Alignments Outlook. - Conclusion: Content Summary Assessment of Contributions Final Statements. Language: English