History of PostgreSQL:
PostgreSQL is an open source relational database originally developed in the 1980s out of the University of California at Berkley. The project leader was Michael Stonebraker, who left Berkeley in 1982 to commercialize his own product called Ingres. He then returned back to Berkley a couple of years later improved upon the work he had started with Ingres called Postgres. He and the other members of his team released several white papers and rules about how Postgres should function. The first one was released in 1986 and continued until the fourth iteration in 1993. The project officially ended with the last release of the fourth iteration; however Berkeley released Postgres under the BSD License which allowed for early open source developers to further develop the program.
The release of the code allowed two graduate students at UC Berkeley to replace the QUEL system with a SQL language interpreter in 1994. This iteration of the program came out as Postgres95. The continued development of Postgres95 by Marc Founier and Vadim Mikheev lead to the first open source release of what is now known as PostgreSQL on August 1st 1996.
What is PostgreSQL:
PostgreSQL is an open source relational database which started life as an Open Source project on August 1st 1996. It has been in constant development for over 15 years by countless contributors to the project. It has risen to be an enterprise class database with many features. These features include Multi-Version Concurrency Control (MVCC), point in time recovery, table-spaces, asynchronous replication, nested transactions, online/hot backups, a sophisticated query planner/optimizer, and write ahead logging for fault tolerance.
PostgreSQL has both open source and commercial support as a relational database. The oldest commercial version of PostgresSQL is Mammoth SQL released by Command Prompt, Inc. in 2001. It also received backing by Pervasive Software in 2005 both commercially and through the community. Other products are well known by the industry because of the Btrieve product which is used on the Novell Netware platform. PostgresSQL has enjoyed more commercial support from several other vendors. The biggest supporter and incorporation of PostgresSQL is Sun Microsystems. In 2005, they announced support for the database, and shipped it with Sun Solaris 10 Operating System in June of 2006.