在Mac上安装Ruby on Rails
http://blog.csdn.net/keyboardota/article/details/8935411
iOS Mac系统下Ruby环境安装
http://www.th7.cn/Program/IOS/201411/307901.shtml
如何快速正确的安装 Ruby, Rails 运行环境
https://ruby-china.org/wiki/install_ruby_guide
原文：http://www.cnblogs.com/pokay/p/4353443.html