>Please tell me if Postgresql runns in an iMac.
If you're on OS X, sure. I'd recommend installing darwinports
(http://darwinports.opendarwin.org), which makes downloading and
compiling as easy as that:
sudo port install postgresql8
darwinports also features several modules for accessing postgresql, I
use psycopg for Python.
On my machine, a 'not-too-current' Powerbook, the combo runs without
any problems.
best regards,
Christoph