Oracle SQL Explorer is available from http://www.oracle.com/technology/software/products/sql/index.html. Like Eclipse and NetBeans, it's Java-based, so there are versions for any operating system that can run Java. It needs release JDK 1.5.0_06 or later of the Java Development Kit. If the installation machine already runs that recent a release of the JDK, you can download a smallish SQL Explorer installer zip; otherwise you need the 100MB+ package. It installs effortlessly.
The MySQL connection requires MySQL Connector/J. If that's not on the machine, download it from http://www.mysql.com/products/connector and install it. Then run SQL Explorer, open Tools | Preferences, in the left pane click on Database, then on Third Party JDBC Drivers. Select Add Entry in the right pane and navigate to where you have a copy of mysql-connector-java-VERSION-bin.jar (where VERSION is something like 5.1.7). Click on it, then on OK. Now you can define a MySQL connection, and when you open that connection, you will have a lovely maintenance interface for your database.