This is Business::OnlinePayment::AuthorizeNet, an Business::OnlinePayment backend module for Authorize.Net. It is only useful if you have a merchant account with Authorize.Net: http://www.authorize.net/ . Business::OnlinePayment is a generic interface for processing payments through online credit card processors, online check acceptance houses, etc. (If you like buzzwords, call it an "multiplatform ecommerce-enabling middleware solution").