At the time of writing, versions of both Ruby 1.8 and 1.9 are available, and version 2.0 is promised for some future date. Currently Ruby 1.8.6, 1.8.7, and 1.9.2 are probably the most widely used versions of Ruby. JRuby also has a pretty strong user base. Several other Ruby interpreters, compilers, and virtual machines are available or are in development. Here is a short list of websites that will provide more information on (and downloads of) implementat-ions of Ruby.

Ruby

The “standard” Ruby implementation

http://www.ruby-lang.org/en/downloads/

JRuby

Ruby for Java

http://www.jruby.org/

IronRuby

An implementation of Ruby for .NET

http://www.ironruby.net/

Rubinius

Compiler/virtual machine for Ruby (written largely in Ruby)

http://www.rubini.us/

MagLev

Fast Ruby implementation (in development)

http://maglev.gemstone.com/