The Castle ActiveRecord project is an implementation of the ActiveRecord pattern for .NET.
The ActiveRecord pattern consists on instance properties re

presenting a record in the database, instance methods acting on that specific record and static methods acting on all records.

Castle ActiveRecord is built on top of NHibernate, but its attribute-based mapping free the developer of writing XML for database-to-object mapping, which is needed when using NHibernate directly.

Check out the Documentation