Nhibernate-nunit is a project mainly written in C#, it's free.
NHibernate 3 setup using Fluent NHibernate and backward compatible settings
This is a simple NHibernate project for .NET.
Create a local database using SQLEXPRESS named MYAPP-LOCAL
Run MyCompany.MyApp.Persistence.TestTestDataBase.cs -> CreateDatabase
Run MyCompany.MyApp.Persistence.TestTestDataBase.cs -> FillDatabase
To merge legacy configuration via App.config with Fluent NHibernate 3 see method InitSessionFactory in MyCompany.MyApp.Persistence.HibernateSessionManager.cs