PostgreSQL
PostgreSQL is an enterprise class Open Source Relational Database Management System (RDBMS) much like Oracle or SQL Server. Postgresql allows organisations to build multiple databases and manage them from a single location. Postgresql is very scalable, comes equipped with a procedural language (like Oracles PLSQL) for developers, supports features like triggers, and has a host of other features. Postgresql has been under development for around 15 years and is a very mature, well supported product that ultimately provides a strong foundation on which to build enterprise solutions.