Original: Software packages that use the MIT License include Expat, PuTTY, the Mono development platform class libraries, Ruby on Rails, Lua 5.0 onwards and the X Window System, for which the license was written.
Simplified: Software that use the MIT License include Expat, PuTTY, Mono development platform class libraries, Ruby on Rails, Cakephp, Twisted, Lua 5.0 onwards and the X Window System, which the license was written for.