The JAX-RS 1.1 specification says on page 6:
If no Application subclass is present the added servlet MUST be named:
javax.ws.rs.core
As I said in the comment above, it all depends on the framework you want to use.
http://syrupsucker.blogspot.com/2008/10/deploying-jersey-in-tomcat-60.html for Jersey http://syrupsucker.blogspot.com/2008/10/deploying-resteasy-in-tomcat-60.html for RESTeasy
As far as I know, JAX-RS does not contain a specification for deployment.