It is fully ACID compliant, has full support for foreign keys, joins, views, triggers, and stored procedures (in multiple languages). It includes most SQL:2008 data types, including INTEGER, NUMERIC, BOOLEAN, CHAR, VARCHAR, DATE, INTERVAL, and TIMESTAMP.
PostgreSQL Global Development Group - 46.26MB (Freeware)
Latest Update
PostgreSQL 9.1.4
Old Versions
PostgreSQL 9.1.3
PostgreSQL 9.1.2
PostgreSQL 9.1.1
PostgreSQL 9.1.0
PostgreSQL 9.0.4
PostgreSQL 9.0.3
PostgreSQL 9.0.2
PostgreSQL 9.0.1