JBoss RESTEasy is a framework that allows you to write RESTFul Web Services in Java. It is a fully certified and portable implementation of JAX-RS specification. JAX-RS is a new JCP specification that provides a Java API for RESTful Web Services over the HTTP protocol.
RESTEasy can run in any Servlet container, but tighter integration with the JBoss Application Server is also available to make the user experience nicer in that environment. While JAX-RS is only a server-side specification, RESTEasy has innovated to bring JAX-RS to the client through the RESTEasy JAX-RS Client Framework. This client-side framework allows you to map outgoing HTTP requests to remote servers using JAX-RS annotations and interface proxies.
Fully certified JAX-RS implementation
Portable to any app-server/Tomcat that runs on JDK 5 or higher
Embeddedable server implementation for junit testing
Rich set of providers for: XML, JSON, YAML, Fastinfoset, Atom, etc.
JAXB marshalling into XML, JSON, Fastinfoset, and Atom as well as wrappers for arrays, lists, and sets of JAXB Objects.
Asynchronous HTTP (Comet) abstractions for JBoss Web, Tomcat 6, and Servlet 3.0
EJB, Spring, and Spring MVC integration
Client framework that leverages JAX-RS annotations so that you can write HTTP clients easily (JAX-RS only defines server bindings)
Special thanks goes to all our independent contributors, specifically: Solomon Duskis, Ryan McDonough, Olivier Brand, Martin Algesten, Michael Brackx, and Justin Edelson.