Ruby is a dynamic, reflective, general purpose object-oriented programming language. Originating in Japan in the mid 1990s, Ruby was initially developed and designed by Yukihiro "Matz" Matsumoto and combines syntax inspired by Perl with Smalltalk-like object-oriented features.

Ruby supports multiple programming paradigms (including functional, object oriented and imperative), and features a dynamic type system and automatic memory management; it is therefore similar in varying respects to Python, Perl, Lisp, Dylan, and CLU.

In its current, official implementation, written in C, Ruby is a single-pass interpreted language. As of 2008, there are a number of alternative implementations of the Ruby language, including Rubinius, JRuby and IronRuby, each of which takes a different approach, with JRuby providing just-in-time compilation functionality.