Survey of [http://www.antipope.org/charlie/linux/shopper/158.databases.html open-source databases] principally examines MySQL, PostgreSQL, and InterBase.
[http://debianlinux.net/databases.html#tools list] of database management tools.
[http://dev.mysql.com/ MySQL]
[http://www.quest.com/toad_for_mysql/index.asp Toad for MySQL] (free trial)
[http://www.navicat.com/ Navicat] GUI for MySQL (free trial)
[http://www.postgresql.org/ PostgreSQL]
[http://www.vitavoom.com/postgresql.html Comparisons] vs. MySQL, InterBase, Oracle.
[http://firebird.sourceforge.net Firebird] is based on InterBase.