Yes, Jarc works with AppEngine. I've been learning AppEngine the last week or so. The CGI-style JarcServlet in the current release, jarc2, isn't an efficient way to go for AppEngine, so I've written a new JarcServlet that loads a single .arc file at init time which defines methods for each URI. I haven't done a new Jarc release, but if you pull the code from CVS, you can get the new JarcServlet. See webapp/servlet.arc for my test code.
