Ruby

Homepage: http://www.ruby-lang.org/

A highly practical general purpose scripting language with an emphasis on Smalltalk-based OOP.

Ruby is known for its popular Web server framework, Ruby on Rails.

Available for a large number of platforms, including mobile devices:
 * .NET (via IronRuby or Rhomobile or XMLVM)
 * Android (via Ruboto or Rhomobile or XMLVM)
 * Blackberry (via Rhomobile)
 * iOS (via RubyMotion or Rhomobile or XMLVM)
 * JavaScript (via Opal)
 * JVM (via JRuby)
 * Linux
 * Mac OS X
 * Windows 7
 * Windows mobile (via IronRuby or Rhomobile or XMLVM)