Ruby is a dynamic, open-source programming language known for its simplicity and productivity. Created by Yukihiro "Matz" Matsumoto in the mid-1990s, it's designed with a focus on simplicity and productivity. Its syntax is easy to read and write, which makes it a popular choice for beginners and experienced developers alike. One of Ruby's most famous applications is Ruby on Rails, a powerful web application framework that has been used to build many popular websites. Think of Ruby as a flexible and friendly language that's perfect for both scripting and building large-scale applications.