In terms of Java, there is the JAX-RS API, which is the Java Api for Xml using Restful Services or something like that. Basically, JAX-RS provides a more standard way to build RESTful services in Java.
There is also Restlet, which allows easily development of Restful services and is based on the JAX-RS specification.
Also, checkout SOAP-UI which has recently added nice support for REST.
http://www.restlet.org/
http://jcp.org/en/jsr/detail?id=311 - JAX-RS
http://www.eviware.com/content/view/134/1/ - SOAP-UI
http://sourceforge.net/projects/soapui - SOAP-UI