In a Business-to-Business (B2B) scenario strategic goals are integration and interoperability. Integration regards the process, within an enterprise, of linking different software systems to become part of larger systems. Interoperability is strictly linked to the standardization of commercial messages and communication protocols. In this work we present the implementation of an environment that provides a common and coherent interface between different trading partners and that can be easily integrated with the computer systems and any B2B middleware used by the enterprises involved in the e-commerce communication. We show how to apply it to connect two B2B middlewares: Oracle B2B, a commercial platform, and Hermes 2.0, an open source project developed by the University of Hong Kong. The commercial transactions are based on the electronic business eXstensible Markup Language (ebXML) standard and the releated ebXML Messaging Services (ebMS) communication protocol. The interactions take place through web applications that provide a common view of the system to the trading partners involved in the communication.