BioMart is a web-based system that allows biologists to perform complex queries across multiple biological databases through a single interface. It integrates data from various sources, enabling users to perform advanced searches and automate queries with its "scripting at the click of a button" feature. BioMart is compatible with several software packages, including BioConductor, Galaxy, Cytoscape, Taverna, and DAS, enhancing its utility for integrated data analysis. The system is designed to be user-friendly, scalable, and accessible, with a wide range of applications in genomics, such as SNP selection, microarray annotation, and disease gene identification. BioMart is freely available at http://www.biomart.org and is used by major biological databases like Ensembl, UniProt, HapMap, Wormbase, Gramene, Dictybase, PRIDE, and Reactome. The system supports both web-based and programmatic access, including Perl API and MartServices, allowing users to generate scripts and perform complex queries efficiently. BioMart's architecture enables integrated querying across distributed data sources, making it a valuable tool for biological research. The system is continuously being improved to enhance data access, simplify querying, and expand its capabilities for data mining and analysis.BioMart is a web-based system that allows biologists to perform complex queries across multiple biological databases through a single interface. It integrates data from various sources, enabling users to perform advanced searches and automate queries with its "scripting at the click of a button" feature. BioMart is compatible with several software packages, including BioConductor, Galaxy, Cytoscape, Taverna, and DAS, enhancing its utility for integrated data analysis. The system is designed to be user-friendly, scalable, and accessible, with a wide range of applications in genomics, such as SNP selection, microarray annotation, and disease gene identification. BioMart is freely available at http://www.biomart.org and is used by major biological databases like Ensembl, UniProt, HapMap, Wormbase, Gramene, Dictybase, PRIDE, and Reactome. The system supports both web-based and programmatic access, including Perl API and MartServices, allowing users to generate scripts and perform complex queries efficiently. BioMart's architecture enables integrated querying across distributed data sources, making it a valuable tool for biological research. The system is continuously being improved to enhance data access, simplify querying, and expand its capabilities for data mining and analysis.