There are many contributions for MS2 that can be found at
osCommerce. Since osCmax uses the BTS template system, small modifications need to be made to most contributions that add changes to the catalog/shopping cart end of osCmax.
Once the small changes have been made, almost all contributions will work perfectly in osCmax. This page details how to install various contributions into osCmax, and details the changes in the install instructions.
Check Permissions :: Runs a check on all the files in your server to make sure they have their permissions set correctly.