This document provides an abstract for a tutorial presentation on reflexive metaprogramming in Ruby. The abstract discusses how Ruby is an object-oriented programming language that has grown in popularity in recent years due to the Ruby on Rails web application framework. Ruby on Rails uses Ruby's flexible syntax and metaprogramming facilities to function as an internal domain-specific language for web applications. The tutorial focuses on Ruby's metaprogramming capabilities, such as querying classes and dynamically defining new classes and methods, which enable internal domain-specific languages like Ruby on Rails.