The document discusses the Open Biomedical Ontologies (OBO) Foundry, which is a collection of reference ontologies in biology and biomedicine that follow a set of principles to ensure logical structure and interoperability. It outlines the motivation and history of OBO Foundry, describes how the ontologies are organized, and provides examples of ontologies in the Foundry and their scopes. The goal of OBO Foundry is to facilitate sharing, integration and analysis of biological data through standardized ontologies.