There is a new product on the market developed by Nevatech. It is called Sentinet. It is built entirely on the Microsoft platform on top of .NET 4.0, WCF, WCF Routing Service and WIF. The product is more powerful, intuitive and does not require any custom coding in order to use it, even though it has a lot of WCF standard and custom extensibility points. It also works in Windows Azure and extends AppFabric Service Bus capabilities. See http://www.nevatech.com/overview.aspx