I've been quite disparaging towards Castle's MonoRail in the past - they really haven't grasped the simplicity of Ruby on Rails as yet. But the technology is getting there, and worth a look. With a revamp (a big revamp) of their site and documentation, this could be a real winner. There are a lot of people who shy away from RoR because of it's Ruby association. A good, clean C# implementation would attract lots of people. I just feel that MonoRail's a little impenetrable as it stands.