RubyOnRails is a Ruby MVC framework for programming web applications. The Rails framework is made up from several parts:

• ActiveRecord?, an ORM library that represents your Models in the MVC pattern
• ActionPack?, which provides the View, and Controller parts of MVC. The views use ERB, or "Embedded Ruby"
• ActiveWebService?, which allows you to provide SOAP and XMLRPC? services integrated into your controllers

• ActiveSupport?, which provides many small niceties, and overrides core Ruby objects to provide things like:

  • 5.days => 432000 (Along with hours, fortnight(s), months, years etc. and kilo, mega, giga, tera-bytes etc.)
  • "person".pluralise => "people" (Also singularise to do the opposite)
  • And lots and lots of other language features, that arguably should be in Ruby anyway (such as Object.tap, Symbol-to-proc, returning "" do ... end)
• ActionMailer?, which sort-of also provides the View part of MVC but for sending (and also receiving) emails

The Rails core code provides the "glue" for all these components.

See http://www.rubyonrails.org/ for more information.