MySQL
Sun Microsystems provides the MySQL database server that powers most of the sites on the Internet and is the database component of the LAMP stack.
While I don't make use of a database for this site I do have a fair number of other sites running Wordpress. So it's handy to have a local copy of the database for testing ( and backup ) so to retrieve a local dump of a remote database issue the following command:
/usr/local/mysql/bin/mysqldump --all-databases
--complete-insert
--create-options
--host=<hostname>
--user=<username>
--password=<password>