Acquia Cloud's Ubuntu 8.04 webservers are Running APC 3.0.19
For full source code, please see:
Due to Acquia's FastCGI implementation a couple of changes need to be made to apc.php in order APC's password protection to work correctly. The included file apc-3.0.19.php includes this patch and works with the included .htaccess
The acquia-apc-info folder should be added to "docroot/sites/all/libraries/" in an Acquia-hosted Drupal repository.
It is highly recommended that you edit the php file and change the username and password.