More or less. Just download the gem from the project page, and "gem install jrexml-0.5.2.gem" (ensuring you're using JRuby's gem command) or "jruby -S gem install
jrexml-0.5.2.gem". I also have the gem hosted on my site, so you can "gem install --source
http://caldersphere.net jrexml" as well.
/Nick