Visual NHibernate makes it easier and quicker to create and maintain NHibernate projects - even very complex ones. Point it at your existing projects and start modelling them right away - visually.
Visual NHibernate makes complex mapping to multiple database tables easy. Simply connect a mapping to a table field and the mapping is complete - all required NHibernate code is generated based on what is mapped.
This is the only tool supporting complex mapping to multiple database tables. (Others only allow one-to-one mapping of tables and classes.) This is a true separation of the domain model and the database schema. Using complex mapping allows optimal software architectures to be built on existing legacy databases without having to redesign the database.