This book constitutes the proceedings of the 24th International Conference on Conceptual Structures, ICCS 2019, held in Marburg, Germany, in July 2019.

The 14 full papers and 6 short papers presented were carefully reviewed and selected from 29 submissions. The proceedings also include one of the two invited talks. The papers focus on the representation of and reasoning with conceptual structures in a variety of contexts. ICCS 2019''s theme was entitled "Graphs in Human and Machine Cognition." 

This book constitutes the proceedings of the 25th International Conference on Conceptual Structures, ICCS 2020, held in Bolzano, Italy, in September 2020.*

The 10 full papers, 5 short papers and 1 poster paper presented were carefully reviewed and selected from 24 submissions. The proceedings also include two keynotes and two tutorials. The papers focus on the representation of and reasoning with conceptual structures in a variety of contexts. The topics of this year''s conference range from formal concept analysis to decision making, from machine learning to natural language processing.

*The conference was held virtually due to the COVID-19 pandemic.

This book constitutes the refereed proceedings of the 18th International Semantic Web Conference, ESWC 2021, held virtually in June 2021.

The 41 full papers and 2 short papers presented were carefully reviewed and selected from 167 submissions. The papers were submitted to three tracks: the research track, the resource track and the in-use track. These tracks showcase research and development activities, services and applications, and innovative research outcomes making their way into industry. The research track caters to both long-standing and emerging research topics in the form of the following subtracks: ontologies and reasoning; knowledge graphs (understanding, creating, and exploiting); semantic data management, querying and distributed data; data dynamics, quality, and trust; matching, integration, and fusion; NLP and information retrieval; machine learning; science data and scholarly communication; and problems to solve before you die.

During ESWC 2021, the following six workshops took place:

1) the Second International Workshop on Deep Learning meets Ontologies and Natural Language Processing (DeepOntoNLP 2021)

2) the Second International Workshop on Semantic Digital Twins (SeDiT 2021)

3) the Second International Workshop on Knowledge Graph Construction (KGC 2021)

5) the 6th International Workshop on eXplainable SENTIment Mining and EmotioN deTection (X-SENTIMENT 2021)

6) the 4th International Workshop on Geospatial Linked Data (GeoLD 2021).

This book constitutes the proceedings of the satellite events held at the 19th Extended Semantic Web Conference, ESWC 2022, during May—June in Hersonissos, Greece, 2022.

The included satellite events are: the poster and demo session; the PhD symposium; industry track; project networking; workshops and tutorials.

During ESWC 2022, the following ten workshops took place:10th Linked Data in Architecture and Construction Workshop (LDAC 2022); 5th International Workshop on Geospatial Linked Data (GeoLD 2022); 5th Workshop on Semantic Web solutions for large-scale biomedical data analytics (SeMWeBMeDA 2022); 7th Natural Language Interfaces for the Web of Data (NLIWOD+QALD 2022); International Workshop on Knowledge Graph Generation from Text (Text2KG 2022); 3rd International Workshop on Deep Learning meets Ontologies and Natural Language Processing (DeepOntoNLP 2022); 1st Workshop on Modular Knowledge (ModularK 2022); Third International Workshop On Knowledge Graph Construction (KGCW 2022); Third International Workshop On Semantic Digital Twins (SeDIT 2022); and the 1st International Workshop on Semantic Industrial Information Modelling (SemIIM 2022).

This book constitutes the post-conference proceedings of the satellite events held at the 20th Extended Semantic Web Conference, ESWC 2023, held in Hersonissos, Greece, during May 28—June 1, 2023.

The 50 full papers included in this book were carefully reviewed and selected from 109 submissions. They were organized in sections as follows: Posters and Demos, Industry, and PhD Symposium.

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.

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.

This book constitutes the refereed proceedings of the 24th International Conference on Knowledge Engineering and Knowledge Management, EKAW 2024, held in Amsterdam, The Netherlands, during November 26–28, 2024.

The 28 full papers presented together were carefully reviewed and selected from 115 submissions. They focus on all aspects of knowledge in constructing systems and services for the semantic web, knowledge management, knowledge discovery, information integration, natural language processing, intelligent systems, e-business, e-health, humanities, cultural heritage, and beyond.

This book constitutes the refereed proceedings of the 15th International Semantic Web Conference, ESWC 2018, held in Heraklion, Crete, Greece.

This book constitutes the proceedings of the 24th International Conference on Conceptual Structures, ICCS 2019, held in Marburg, Germany, in July 2019.

The 14 full papers and 6 short papers presented were carefully reviewed and selected from 29 submissions. The proceedings also include one of the two invited talks. The papers focus on the representation of and reasoning with conceptual structures in a variety of contexts. ICCS 2019''s theme was entitled "Graphs in Human and Machine Cognition." 

This book constitutes the proceedings of the 25th International Conference on Conceptual Structures, ICCS 2020, held in Bolzano, Italy, in September 2020.*

The 10 full papers, 5 short papers and 1 poster paper presented were carefully reviewed and selected from 24 submissions. The proceedings also include two keynotes and two tutorials. The papers focus on the representation of and reasoning with conceptual structures in a variety of contexts. The topics of this year''s conference range from formal concept analysis to decision making, from machine learning to natural language processing.

*The conference was held virtually due to the COVID-19 pandemic.

This book constitutes the refereed proceedings of the 18th International Semantic Web Conference, ESWC 2021, held virtually in June 2021.

The 41 full papers and 2 short papers presented were carefully reviewed and selected from 167 submissions. The papers were submitted to three tracks: the research track, the resource track and the in-use track. These tracks showcase research and development activities, services and applications, and innovative research outcomes making their way into industry. The research track caters to both long-standing and emerging research topics in the form of the following subtracks: ontologies and reasoning; knowledge graphs (understanding, creating, and exploiting); semantic data management, querying and distributed data; data dynamics, quality, and trust; matching, integration, and fusion; NLP and information retrieval; machine learning; science data and scholarly communication; and problems to solve before you die.

During ESWC 2021, the following six workshops took place:

1) the Second International Workshop on Deep Learning meets Ontologies and Natural Language Processing (DeepOntoNLP 2021)

2) the Second International Workshop on Semantic Digital Twins (SeDiT 2021)

3) the Second International Workshop on Knowledge Graph Construction (KGC 2021)

5) the 6th International Workshop on eXplainable SENTIment Mining and EmotioN deTection (X-SENTIMENT 2021)

6) the 4th International Workshop on Geospatial Linked Data (GeoLD 2021).

This book constitutes the proceedings of the satellite events held at the 19th Extended Semantic Web Conference, ESWC 2022, during May—June in Hersonissos, Greece, 2022.

The included satellite events are: the poster and demo session; the PhD symposium; industry track; project networking; workshops and tutorials.

During ESWC 2022, the following ten workshops took place:10th Linked Data in Architecture and Construction Workshop (LDAC 2022); 5th International Workshop on Geospatial Linked Data (GeoLD 2022); 5th Workshop on Semantic Web solutions for large-scale biomedical data analytics (SeMWeBMeDA 2022); 7th Natural Language Interfaces for the Web of Data (NLIWOD+QALD 2022); International Workshop on Knowledge Graph Generation from Text (Text2KG 2022); 3rd International Workshop on Deep Learning meets Ontologies and Natural Language Processing (DeepOntoNLP 2022); 1st Workshop on Modular Knowledge (ModularK 2022); Third International Workshop On Knowledge Graph Construction (KGCW 2022); Third International Workshop On Semantic Digital Twins (SeDIT 2022); and the 1st International Workshop on Semantic Industrial Information Modelling (SemIIM 2022).

This book constitutes the post-conference proceedings of the satellite events held at the 20th Extended Semantic Web Conference, ESWC 2023, held in Hersonissos, Greece, during May 28—June 1, 2023.

The 50 full papers included in this book were carefully reviewed and selected from 109 submissions. They were organized in sections as follows: Posters and Demos, Industry, and PhD Symposium.

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.

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.

This book constitutes the refereed proceedings of the 24th International Conference on Knowledge Engineering and Knowledge Management, EKAW 2024, held in Amsterdam, The Netherlands, during November 26–28, 2024.

The 28 full papers presented together were carefully reviewed and selected from 115 submissions. They focus on all aspects of knowledge in constructing systems and services for the semantic web, knowledge management, knowledge discovery, information integration, natural language processing, intelligent systems, e-business, e-health, humanities, cultural heritage, and beyond.

This book constitutes the refereed proceedings of the 15th International Semantic Web Conference, ESWC 2018, held in Heraklion, Crete, Greece.