I used TOAD for a while for browsing around Oracle databases. Good stuff, though the free version is a bit limited, and Quest Software, who sell it, have the annoying thing of not selling it retail, but negotiating licence prices, making purchasing it a long drawn-out process.

Turns out there’s now an alternative: Oracle’s SQL Developer, which does a pretty good job at doing the same thing, and it’s free. It runs on Windows, Mac and Linux, and it uses Java and the JDBC client and apparently doesn’t need the humungous Oracle client software (though I haven’t actually verified that yet).

(Tony found the SQL Server equivalent some time ago, though it’s moved slightly. MySQL? MySQL GUI Tools.)