RoboZombie allows easy integration with remote services by allowing you to replicate an endpoint contract and generate a proxy to access it. Contracts can be very flexible in terms of the resources they access. These could be vary from static HTML content or an RRS feed, to a RESTful web service endpoint. Each endpoint contract is specified on a single interface using annotations to provide the communication metadata. It is then wired into your code via an annotation, where it is created, cached, and injected at runtime.
Fulworx is a REST framework that uses simple annotations of XWork "Action" implementations to expose restful interfaces. Similar to Struts, Fulworx sits as a controller on top of Restlet. Each action is attached as a resource using Restlets. Standard resources are represented by default as XML (or JSON) using JAXB, but any representation may be specified. Actions may be used in other frameworks such as Struts and Webwork, since they're just XWork implementations.
RestyGWT is a GWT generator for REST services and JSON encoded data transfer objects. RestyGWT Rest Services allow you to define an asynchronous service API which is then implemented via GWT deferred binding by RestyGWT. It features generation of asynchronous RESTful JSON based service proxies, encoding and decoding of Java objects to JSON, and an easy-to-use REST API.