Out of the box, Windows Communication Foundation is perfectly suited for simple WCF-to-WCF exchanges. However, the diverse communication requirements of most real world applications aren’t simple. For interactions with a high-availability client application, for instance, performance is paramount. Interoperability is straightforward, if the client and service are built on the .NET Framework. For communication with an existing Java EE-based application or with diverse partner applications, however, interoperability becomes the highest goal.