Ruby is indeed the heart of the Metasploit framework. However, what exactly is Ruby? According to the official website, Ruby is a simple and powerful programming language and was designed by Yokihiru Matsumoto in 1995. It is further defined as a dynamic, reflective, and general-purpose object-oriented programming language with functions similar to Perl.
You can download Ruby for Windows/Linux from: https://rubyinstaller.org/downloads/.
You can refer to an excellent resource for learning Ruby practically at: http://tryruby.org/levels/1/challenges/0.
