ZINC15 is a comprehensive and user-friendly database and toolset designed to bridge the gap between chemoinformatics and biology. It offers over 120 million purchasable "drug-like" compounds, with a quarter available for immediate delivery. The platform integrates biological activity, chemical property, and commercial availability data from various sources, enabling users to query and analyze compounds based on their biological effects, chemical properties, and commercial availability. Key features include: 1. **Ligand Annotation**: Compounds are annotated with biological activity, chemical properties, and commercial availability. 2. **Query Language and Report Generator**: A web URL-compatible query language and report generator facilitate complex queries. 3. **Graphical User Interface**: A user-friendly interface that does not require programming skills. 4. **New Analysis Tools**: Easy-to-use tools for nonexperts with limited limitations for experts. ZINC15 connects purchasable compounds to high-value ones such as metabolites, drugs, natural products, and annotated compounds from literature. Users can access compounds by gene products, target classes, and major and minor target classes. The platform supports focused libraries of ligands and provides detailed information on compounds, including purchasing details, biological activity data, and chemical patterns. The article highlights the expansion of ZINC's capabilities, including the ability to identify and link compounds to biological targets and processes. It also demonstrates how ZINC15 can answer previously difficult questions, such as the number of endogenous human metabolites and their purchasability. The platform is freely available at http://zinc15.docking.org.ZINC15 is a comprehensive and user-friendly database and toolset designed to bridge the gap between chemoinformatics and biology. It offers over 120 million purchasable "drug-like" compounds, with a quarter available for immediate delivery. The platform integrates biological activity, chemical property, and commercial availability data from various sources, enabling users to query and analyze compounds based on their biological effects, chemical properties, and commercial availability. Key features include: 1. **Ligand Annotation**: Compounds are annotated with biological activity, chemical properties, and commercial availability. 2. **Query Language and Report Generator**: A web URL-compatible query language and report generator facilitate complex queries. 3. **Graphical User Interface**: A user-friendly interface that does not require programming skills. 4. **New Analysis Tools**: Easy-to-use tools for nonexperts with limited limitations for experts. ZINC15 connects purchasable compounds to high-value ones such as metabolites, drugs, natural products, and annotated compounds from literature. Users can access compounds by gene products, target classes, and major and minor target classes. The platform supports focused libraries of ligands and provides detailed information on compounds, including purchasing details, biological activity data, and chemical patterns. The article highlights the expansion of ZINC's capabilities, including the ability to identify and link compounds to biological targets and processes. It also demonstrates how ZINC15 can answer previously difficult questions, such as the number of endogenous human metabolites and their purchasability. The platform is freely available at http://zinc15.docking.org.