This is how I ruby on Emacs. This is all based on top of the the built in ruby-mode. I’m using emacs 25 built by homebrew on OSX.
##ELPA Packages##
- rspec-mode - Enhance ruby-mode for RSpec
- ruby-block - highlight matching block
- ruby-compilation - run a ruby process in a compilation buffer
- ruby-end - Automatic insertion of end blocks for Ruby
- ruby-interpolation - Ruby string interpolation helpers
- ruby-tools - Collection of handy functions for ruby-mode