Ruby: www.ruby-lang.org
Active Record—Object-relation mapping put on rails: api.rubyonrails.org/files/vendor/rails/activerecord/README.html
Martin Fowler on Active Record: www.martinfowler.com/eaaCatalog/activeRecord.html
SOAP4R: dev.ctor.org/soap4r
WEBrick: www.webrick.org
Builder: builder.rubyforge.org