There is a new release of Oracle SQL Developer available. It is version 2.1. This has two new big features. They are PL/SQL unit testing and a Data Modeler/Viewer.
The PL/SQL unit testing part is a unit test framework. It allows you to share unit tests. It also let’s you run regression tests.
The Data Modeler/Viewer gives you read only access to a database schema. You can view the schema objects graphically. A benefit is the ability to browse the foreign keys between tables.
To tell the truth, there is even a version 2.1.1 patch that is available now. The big v2.1 release is 94M large for the install. It requires the Java Development Kit v1.6 update 11..
This app is still free of charge. You can still edit PL/SQL just like the older versions of the tool. And it still integrates with all kinds of source code control.