How to Install Ruby (on Rails) on Mac
macOS already included Ruby. You can type ruby -v at a Terminal prompt to check Ruby version and see result like: ruby 2.3.3p222 (2016-11-21 revision 56859) [universal.x86_64-darwin17] If you are satisfied with the Ruby version, you can type gem install rails --no-ri --no-rdoc to install Rails. However, if you are not satisfied with the Ruby version or if you have multiple apps that run on different Ruby version, I would recommend you use RVM to manage Ruby. ...