title: What are some good open source c# examples of quality domain models
body: <p>I'm a pretty young developer, and still in the emulation phase of my career.  I have read a lot about some topics like concurrency, and using unit of work to allow your business layer to control persistence transactions.  I have even implemented some painful, but functional code that implements these topics. But I have not really ever seen a real world example of a truly elegant implementation.  I don't have a lot of good TDD, pattern focused role models around me, so I'm forced to look at the outside world for guidance.</p>
  
  <p>So, I'm looking for some stellar examples of open source enterprise app domain models. Preferably written in c#, but other languages would be fine as well as long as they are good examples of clean elegant domain model solutions.</p>
  
  <p>Some of the things I would really like to see are elegant solutions for Concurrency, Business Rules and Object Validation, Transactions / Unit of Work, and semi transparent logging mechanisms. I'm also curious to see what some of the real world best practices are for exception handling in domain model code.</p>
  
  <p>I know I could just start tearing into some open source projects at random, and try to decipher the good from the bad, but I was hoping the expert community here would have some good ideas of projects to look at to stream line the effort.</p>
  
  <p>Thanks for your time.</p>
  
  <h2>Edit</h2>
  
  <p>I'm not really interested in frameworks that make design and construction easier.  My choice of framework, or whether to use a framework is a necessary consideration, but is entirely separate from my question here.  Unless those frameworks are themselves open source, and very good examples to dig through.</p>
  
  <p>What I am looking for is a project that 'got it right', solving a real world problem with code that is flexible, and easily maintainable, so that I can see with my own eyes, and understand an example of how it should be done that is not a trivial 50 line tutorial example.</p>