IBM DB2

DB2 is the database management system that delivers a flexible and cost-effective database platform to build robust on demand business applications.

http://www.ibm.com/software/data/db2/

SQL Server is a comprehensive, integrated, end-to-end data solution that empowers your people by providing a more secure, reliable, and productive platform for enterprise data and BI applications.

http://www.microsoft.com/sql/

The MySQL Enterprise Server software is the most reliable, secure and up-to-date version of the world's most popular open source database for cost-effectively delivering E-commerce, Online Transaction Processing (OLTP), and multi-terabyte Data Warehousing applications.

http://www.mysql.org

Oracle Databases deliver record-breaking performance and scalability on Windows, Linux, and UNIX servers. Oracle Databases deliver better results by automating administrative tasks, providing industry-leading security and regulatory compliance features, and enabling the highest availability with Real Application Clusters.

http://www.oracle.com/database

Apache Derby is an open source relational database implemented entirely in Java.

http://db.apache.org/derby