I'm not familiar with DWR, but, from a quick look at the linked page, it does appear to be conceptually similar to CGI::Ajax, in that CGI::Ajax provides a simple way for a web page to call a server-side Perl subroutine and insert that sub's output into a div (or pass it as input to a javascript function) on the calling page and DWR looks like it does the same for server-side Java code.