Centos

From OEMR

Centos has a reputation for extreme stability which appeals to me.

Required modules:

php
php-cli
php-common
php-ldap
php-mysql
php-pdo

For the MI-Squared.com LabCorp and other interfaces:

php-soap

For the MI-Squared and Z&H Healthcare eRx:

php-xml

I like to rum mediawiki in my office for document management. "MediaWiki 1.18 requires at least PHP version 5.2.3, you are using PHP 5.1.6."