What is the current best validation framework for asp.net apps?

To make sure its a DRY approach all validation logic should of course go in the business logic (model).

• How are validation messages presented to views, should be able to localize error messages
• Can you generate javascript from the validation framework. Compatibility with JQuery would be perfect
• Is the framework compatible with a DbC approach?

Edit: I think this is the nicest one until now, Castle validator + live validation http://blog.codeville.net/2008/04/30/model-based-client-side-validation-for-aspnet-mvc/

From stackoverflow

• Validation Application Block

  from Microsoft is one alternative but I have no experience with it