PostgreSQL

On-line docs for PostgreSQL:
http://www.postgresql.org/docs/8.2/static/index.html

Taken from a post by Barry J.:

I use XAMPP on Windows for development. Here is my process for using PostgreSQL 8.3:

1. Download and run the installer.
2. Uncomment the "extension=php_pgsql.dll" line in Apache's php.ini.
3. Re-start Apache.
4. Change $db_url in settings.php.

Taken from a post by Bill M.:

Once it's installed, there's another step called "initializing