This site http://www.java2s.com/Code/Jar/o/org.restlet.htm has a list of restlet jars. But not the 2.1 revision. When I go to the official site http://www.restlet.org/downloads/testing, they don't have the jars. Is there a place where I can find the 2.1 jar? I am interested in the Java SE edition.
I downloaded the restlet 2.1rc6 zip file from the http://restlet.org/ link you provided, the jar files are in the lib directory. There are a bunch of sub directories containing the jar files. Version 2.1 Release Candidate 6 Edition for Java SE Zip Archive (The 2nd link down).