BioMart is the data access site of the Ensembl Genome Browser from EMBL-EBI. It contains data for the tracks in the Ensembl Genome Browser, and can be queried via the web or through R packages like biomaRt. This guide demonstrates the use of the BioMart web service.
Sometimes you may want to retrieve sequences or genomic features in text (or table) format, without viewing them in a genome browser graphical view first. BioMart allows you to set your genome, filter by feature or region, and retrieve only the fields you want from the MANY tables of data available in Ensembl Genome Browser.
Examples of the use of BioMart:
BioMart can be accessed from the Ensembl home page. When you go to the Ensembl home page, you may be directed to your nearest Ensembl web server/mirror (such as "US East" or "US West". If your nearest mirror is down for maintenance, you will be offered links to the other mirrors available.
Click on the "BioMart >" link in the Tools section at the top of the page, or the "BioMart" menu in the topmost menu of the site.
You can also Google "Ensembl BioMart" and use links to access the web service.