JRuby offers a server mode called "nailgun" that helps to offset the pain of starting up a new copy of the JVM for each script. Nailgun starts a copy of JRuby up and listens on a port for future jruby calls thereby bypassing the usual JVM startup cost.

1. Make sure you have nailgun installed.

 % cd /path/to/jruby/tool/nailgun
 % ./configure
 % make

2. Start the nailgun server in the background.

 % jruby --ng-server &

3. To use nailgun for executing your scripts, pass the --ng command line switch.

 % jruby --ng myscript.rb