DbVisualizer is a cross platform database tool that aims to increases user productivity by providing a single solution to speed development, testing and administration of relational databases.

For develpers, it offers a range of tools to assist database development and perform tasks such as object browsing, creating, running SQL statements and SQL scripts plus viewing and editing data. It's pretty powerful as it supports all major commercial databases including Oracle, DB2, Mimer, SQL Server, Sybase ASE, Informix and open source alternatives such as MySQL, PostgreSQL and JavaDB/Derby.

Most recently, it's been updated to include a Table Data Navigator which allows you to navigate foreign keys based on data selections. This is useful when browsing normalized tables with keys to other tables. It also supports visual creation and the editing of table definitions including columns, indexes, primary, foreign keys, constraints and non standard features specifically for the supported databases.

If you need something that supports multiple databases in one package, you can't go far wrong with DbVisualizer but it's severely lacking in instructional information to guide you through the database management process.