OK, so you wanna connect to your MsSQL Database from your CentOS box. Most of these steps should be easily replicated on your CentOS version of choice, but in my case I'm using CentOS 4.4 and the latest version of PHP
$ cat /etc/redhat-release CentOS release 4.4 (Final) $ rpm -q php php-4.3.9-3.22.4