Ruby kernel on Colab

!apt-get install ruby-dev
!sudo apt install libtool libffi-dev ruby ruby-dev make
!sudo apt install libzmq3-dev libczmq-dev
!gem install ffi-rzmq
!gem install specific_install
!gem specific_install https://github.com/SciRuby/iruby
!iruby register

!jupyter kernelspec list

Available kernels:
  ruby       /root/.local/share/jupyter/kernels/ruby
  ir         /usr/local/share/jupyter/kernels/ir
  python2    /usr/local/share/jupyter/kernels/python2
  python3    /usr/local/share/jupyter/kernels/python3