Binaries here: http://sourceforge.net/projects/nhibernate/files/.
Release notes: https://nhibernate.jira.com/secure/ReleaseNote.jspa?projectId=10000&version=10440.
JIRA issue tracking: https://nhibernate.jira.com.
As always, you can get help from the NHibernate Users mailing list: http://groups.google.com/group/nhusers.
Lots of bug fixes and some new features. My favorite ones are:
Mapping by code: fluent configuration, no more .hbm.xml files required;
Subselect: ability to map SQL views as entities;
HQL paging: TAKE and SKIP on HQL;
Integrated bytecode provider: one less DLL to deploy.
Read more: Development With A Dot
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