I have been using Fluent Nhibernate instead of Nhibernate with xml config files.
It is definitely helpful in preventing configuration typos.
There other contrib projects for Nhibernate that I have found extremely useful
including Nhibernate Validator and NHibernate Spatial.
Nhibernate is independent from Hibernate and it doesn't benefit from a large corporate backer. Due to this Nhibernate and contrib projects are spread across multiple websites.
Main Site:
Fluent Nhibernate:
Moved, again
10 years ago