-- Research. -- Do Similar Entities have Similar Embeddings. -- Treat Different Negatives Differently Enriching Loss Functions with Domain and Range Constraints for Link Prediction. -- QAGCN Answering Multi-Relation Questions via SingleStep Implicit Reasoning over Knowledge Graphs. -- Leveraging Pretrained Language Models for Time Interval Prediction in TextEnhanced Temporal Knowledge Graphs. -- A Language Model based Framework for New Concept Placement in Ontologies. -- HolmE LowDimensional Hyperbolic Knowledge Graph Embedding for Better Extrapolation. -- SCBlock Supervised Contrastive Blocking within Entity Resolution Pipelines. -- Navigating Ontology Development with Large Language Models. -- ESLM Improving Entity Summarization by Leveraging Language Models. -- Explanation of Link Predictions on Knowledge Graphs via Levelwise Filtering and Graph Summarization. -- Large Language Models for Scientific Question Answering an Extensive Analysis of the SciQA Benchmark. -- Efficient Evaluation of Conjunctive Regular Path Queries Using Multiway Joins. -- Can Contrastive Learning Refine Embeddings. -- InUse. -- Automation of Electronic Invoice Validation using Knowledge Graph Technologies. -- Towards Cyber Mapping the German Financial System with Knowledge Graphs. -- Integrating domain knowledge for enhanced concept model explainability in Plant Disease classification. -- Generative Expression Constrained Knowledgebased decoding for Open data. -- OntoEditor Realtime Collaboration via Distributed Version Control for Ontology Development.

The two-volume set LNCS 14664 and 14665 constitutes the refereed proceedings of the 21st International Conference on The Semantic Web, ESWC 2024, held in Hersonissos, Crete, Greece, during May 26-30, 2024. The 32 full papers presented were carefully reviewed and selected from 138 submissions. They focus on all aspects of theoretical, analytical, and empirical aspects of the semantic web, semantic technologies, knowledge graphs and semantics on the web in general.