Toad for SQL Server provides a development UI that improves productivity

TOAD® empowers developers and DBAs to be more productive by providing an intuitive graphical user interface to Oracle. TOAD is a powerful, low-overhead tool that makes PL/SQL development faster and easier and simplifies database administration.

Toad for MySQL leverages Quest Software's database expertise to empower MySQL developers and administrators, of varying skill levels, to rapidly create and execute queries, automate database object management and develop SQL code more efficiently.

Powerful database design tool which allows you to visually create Entity Relationship Diagrams (ERD) for various database systems - Oracle, DB2, MS SQL, MySQL, InterBase, Sybase etc. Features: ERD, SQL script generation, Reverse engineering...

Toad® for DB2 UDB is a database development solution that provides productivity features for rapidly creating and executing queries, automating database object management, developing SQL code, and instant access to DB2 expertise.

Powerful database design tool which allows you to visually create Entity Relationship Diagrams (ERD) for various database systems - Oracle, DB2, MS SQL, MySQL, InterBase, Sybase etc. Features: ERD, SQL script generation, Reverse engineering...

Happy Fish is a ERD database design tool which supports multiple database platforms. Create a complete and attractive ERD diagram design with domains, tables, foreign keys, views, stored procedures and more.

You can use this application to create UML,ER,ERD,state diagrams,network topology schema,Cisco networks,component models,process models,business models. In many ways - this application contain more functions than Microsoft Visio and it is free.