Pro3 Online technology
Pro3 Online is an SharePoint Online add-on developed using the Microsoft SharePoint Provider Hosted App model. The add-on can be installed in a customer's existing SharePoint Online subscription. The data and content are always stored in the customer's SharePoint subscription tenant and the Pro3 extension is installed in a cloud web service such as Microsoft Azure.
The Provider Hosted App Model guarantees the functionlaity of the system even when SharePoint Online is updated. The add-in extends SharePoint with the same functionalities as the on-premisis Pro3.