Sfeb is a Simple and Flexible Enterprise Bus. Its purpose is to share business components on a network, and make them accessible through various protocols(http, jms, ...). Sfeb can be adapted, to your needs with the Sfeb sdk.
XSpace is a globally accessible repository for hierarchically-keyed information. It provides persistence for trees with an elegant tree-navigation API. XSpace also publishes real-time events whenever a persisted tree is updated.
Web Objects in XML (Framework) is an interoperable and lightweight system for distributed objects. It is currently built in Java and C#. Remote objects are serialized in a standard XML format, and they are accessible trough their own URL.