PostgreSQL is a robust, next-generation, Object-Relational DBMS (ORDBMS),
derived from the Berkeley Postgres database management system.  While
PostgreSQL retains the powerful object-relational data model, rich data types
and easy extensibility of Postgres, it replaces the PostQuel query language
with an extended subset of SQL.

PostgreSQL is free and the complete source is available.

This package contains the database documentation.

Homepage:
http://www.postgresql.org/
