DB2
http://www-306.ibm.com/software/data/db2/DB2 Product Family
Information Management software
DB2 Universal Database is the database management system that delivers a flexible and cost-effective database platform to build robust on demand business applications. DB2 UDB further leverages your resources with broad support for open standards and popular development platforms like J2EE and Microsoft .NET. The DB2 UDB family also includes solutions tailored for specific needs like business intelligence and advanced tooling. Whether your business is large or small, DB2 UDB has a solution built and priced to meet your unique needs.
PostgreSQL
http://www.postgresql.orgWhat is PostgreSQL? How is it pronounced?
PostgreSQL is pronounced Post-Gres-Q-L, and is also sometimes referred to as just Postgres. An audio file is available in MP3 format for those would like to hear the pronunciation.
PostgreSQL is an object-relational database system that has the features of traditional commercial database systems with enhancements to be found in next-generation DBMS systems. PostgreSQL is free and the complete source code is available.
PostgreSQL development is performed by a team of mostly volunteer developers spread throughout the world and communicating via the Internet. It is a community project and is not controlled by any company. To get involved, see the developer's FAQ at http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html