Holodeck B2B is a standalone application that provides the AS4 messaging capability to your solution. The Holodeck B2B gateway takes care of all complexity related to the message exchange with your trading partner, the business application only needs to provide the business documents and some meta-data telling Holodeck B2B who to send the data to.
The open source version provides a simple file based integration method with the business application.
Using Holodeck B2B’s extension mechanism additional customised connectors can be plugged into the gateway. These can be tailored to the specific requirements of your environment and for example handle validation and transformation of the business data.