The Google Checkout module for osCMax allows merchants using osCMax to offer Google Checkout as an alternate checkout method. The plugin provides Level 2 integration of Google Checkout with osCMax. This module is a direct port of the Google Checkout module for osCommerce
This module implements PayPal Website Payments Pro which consists of PayPal's Express Checkout and Direct Payment methods.
I ported this to work with RC3 included.
This module does not use the PayPal PHP SDK so the installation is fairly easy.