JRubyインストール

JRuby Ubuntu 
sudo apt-get install sun-java6-jdk sun-java6-bin


aptのjrubyが古いのでバイナリを持ってくる

wget http://jruby.org.s3.amazonaws.com/downloads/1.5.1/jruby-bin-1.5.1.tar.gz
tar -zxvf jruby-bin-1.5.1.tar.gz
mv jruby-1.5.1 ~/lib/jruby


.zshrc

path=($HOME/local/bin $HOME/local/X11R6/bin \
    /bin /usr/local/bin /usr/bin /var/lib/gems/1.8/bin $HOME/lib/jruby/bin)

export GEM_HOME=/usr/lib/ruby/gems/1.8

GEM_HOMEはCRubyと共有