NHibernate 4.0.1 General Availability is now available for download from Sourceforge and Nuget.

http://sourceforge.net/projects/nhibernate/?source=directory

This includes fixes for regressions in NH 4.0.0, and some fixes for mapping-by-code and Firebird issues.

Please see the full release notes for more information:

https://github.com/nhibernate/nhibernate-core/blob/4.0.1.GA/releasenotes.txt

Full list of changes:

[4.0.1.GA] https://nhibernate.jira.com/issues/?jql=project%20%3D%20NH%20AND%20resolution%20%3D%20Fixed%20AND%20fixVersion%20%3D%204.0.1