Is PKP hosting free? what are the differences?
To use OJS, you have a few options:
Download and run it yourself, with no charge from PKP.
Pay PKP to host your journal for you through our PKP Publishing Services. All revenue goes directly back into developing our free, open source software for everyone.
Work with a third party service provider. Some provide hosting for free (such as many academic libraries) and some charge a fee, such as the unaffiliated service provider you mentioned.
Thank you for your information.