Summary: EMBL is good to use when you need a limited amount of data and when you are not trying to identify a gene by sequence analysis. However, because EMBL and all of its mirror sites are located in Europe, your connection will be slow more often than not. All of the information submitted to EMBL is mirrored daily in both GenBank and DDBJ, so searching elsewhere might provide the same amount of information in less time.
EMBL is the database for the European Molecular Biology Laboratory. It is a flat-file database that is searched by a multitude of various search engines. EMBL sequences are stored in a form corresponding to the biological state of the information in vivo. Thus, cDNA sequences are stored in the database as RNA sequences, even though they usually appear in the literature as DNA.