The latest versions of OJS and OCS support interoperability with the popular PayPal online payment system. It will allow you to collect a variety of registration, author submission, donation, and other fees securely and online -- without your users needing to have a PayPal account at all.

To get started, take a look at the document "Using PayPal for OJS and OCS Payments". It outlines the steps required to create a PayPal account and configure OJS and OCS to collect secure online payments.