1. SQLite

SQLite is a small SQL database engine that is self-contained, embeddable, and zero-configuration.

2. MySQL

MySQL is a fast and reliable database system. MySQL empowered million high-volume Web sites and other critical business systems. It is suitable for corporate IT departments, Web developers and packaged software vendors.

3. DB2

DB2 Universal Database (UDB) is a relational database management system (RDBMS) developed by IBM for cross-platform.

4. Oracle

Oracle Database 10g is the first relational database designed for Grid Computing that makes information always available and secure.

5. SQL Server

SQL Server provides the enterprise data management platform that supports Extensible Markup Language (XML) and Business Intelligence (BI).

6. PostgreSQL

PostgreSQL is a highly scalable, SQL compliant, object-relational database management system.