MODULARITY, as studied for many years in software engineering, allows mechanisms for easy and flexible reuse, generalization, structuring, maintenance, design patterns, and comprehension. Applied to ontology engineering, modularity is central not only to reduce the complexity of understanding ontologies, but also to facilitate ontology maintenance and ontology reasoning.

Recent research on ontology modularity shows substantial progress in foundations of modularity, techniques of modularization and modular development, distributed reasoning and empirical evaluation. These results provide a foundation for further research and development.

TOPICS include, but are not limited to:

- What is Modularity: Kinds of modules and their properties; modules vs. contexts; design patterns; granularity of representation;

- Logical/Foundational Studies: Conservativity and syntactic approximations for modules; modular ontology languages; reconciling inconsistencies across modules; formal structuring of modules; heterogeneity;

- Algorithmic Approaches: distributed reasoning; modularization and module extraction; (selective) sharing and re-using, linking and importing; hiding and privacy; evaluation of modularization approaches; complexity of reasoning; reasoners or implemented systems;

- Applications: Semantic Web; Life Sciences; Bio-Ontologies; Natural Language Processing; ontologies of space and time; Ambient Intelligence; collaborative ontology development; etc.