Qlobe is a fascinating example of quine in Ruby, submitted by a member of the Ruby core team - Yusuke Endoh.
Programs that output changed executable versions of themselves while managing to spin the globe and still remaining executable are cool, right?
To experience its magic, run the following
curl -fSSl https://gist.githubusercontent.com/shime/f0ebe84ca42c33b51d42/raw/5e74315dc6b6fe572f8a457536ad7eb17ad3f1e4/qlobe.rb > qlobe.rb; while true; do ruby qlobe.rb | tee temp.rb; sleep 1; mv -f temp.rb qlobe.rb; done