Ensembl
Ensembl is a joint project between EMBL and the Wellcome Trust Sanger Institute to develop a software system which produce and maintains automatic annotation on selected eukaryotic genomes. From the Ensembl main page, you can type a text query, perform a database query for sequence data or browse by chromosomes. There are different entry points to access the database. It is possible to search for genes, chromosomal locations, small nucleotide polymorphisms (SNP), etc.
Please direct questions and comments to Martin Haubrock.