anchor.diff:  
     has_many :articles, :repository => :ArticleRepository
   end
  -```
  +----
   
   === Aggregates
   
  
positive.code: 
  Because Paul wanted to learn Ruby and see how well it supports DDD. Also, interested in questions like:
  
  * How does the choice of Ruby affect the implementation of the DDD building block patterns? 
  * How well does an opinionated MVC framework like Rails support doing DDD? 
  * What are implications of choosing a document store like MongoDB for aggregate design and eventual consistency?
  
  === Why a DDD Sample App?
  
negative.code: ==== Mongo ORMs
  
  * http://mongoid.org/en/mongoid/index.html[Mongoid] -  Object-Document-Mapper (ODM) for MongoDB written in Ruby. Has Echo sample app - take a look at `application.rb` - it's using Sidekiq and Kiqstand (not sure what for...maybe could be used for aggregate updates?)
  * https://github.com/mongomatic/mongomatic[Mongomatic] -  A MongoDB super-set that adds nice features over the traditional Ruby Driver. Map your Ruby objects to Mongo documents. It is designed to be fast and simple.
  * http://mongomapper.com/[MongoMapper] - ODM for MongoDB written in Ruby.
  
  === Repository Pattern in Ruby
  
  * http://mattbriggs.net/blog/2012/02/23/repository-pattern-in-ruby/
  * https://github.com/nfedyashev/repository[A Ruby implementation of the Repository Pattern - In memory only], developed from https://github.com/alexch/treasury[Repository Pattern for Ruby - 3 years old].
  * https://github.com/playlouder/persistence[A set of interfaces for, and implementations of, the Repository pattern in Ruby.] This one looks promising.
  * https://github.com/brandonweiss/collector[Collector is an implementation of the Repository Pattern for MongoDB]
  * https://github.com/braintree/curator[Curator is a model and repository framework for Ruby].Currently, curator supports Riak, MongoDB and an in-memory data store for persistence.
  