Installing Ruby on Windows, Mac and Linux
Install Alongside Ruby 1.8.x--Upgrading to Ruby 1.9.1
Install Ruby 1.9.1 on your Linux machine alongside your current Ruby 1.8.x distribution to upgrade it. You'll have to compile the code from source, as shown in this tutorial.
Install Ruby on Windows
How to install the Ruby interpreter on the Windows operating system.
Install Ruby on Linux
How to install Ruby on the Linux operating system.
Install Ruby on OS X
How to install Ruby on Apple OS X
Installing jRuby With RVM on OS X
As with most flavors of Ruby, the easiest, cleanest and least painful way to install jRuby is with RVM, the Ruby Version Manager. And although jRuby is different than MRI, the official Ruby interpreter, it can be installed just as easily, arguably easier.
Instructions for installing Ruby on Windows, Mac OS X and Linux as well as instructions for installing a few Ruby-related extras.
Visual Tutorial: Installing Ruby on Windows
A visual walkthrough on installing Ruby on Windows.
Installing a Ruby Development Environment on Windows
In the past, the Ruby “One-Click Installer” was the primary choice for installing Ruby on Windows. However, the One-Click Installer fell into disrepair and was eventually abandoned. Something new was needed, and thus, RubyInstaller was born.