Top 20 NuGet ORM Packages

Cache provider for NHibernate using MemoryCache.
Enables the usage of NodaTime types with NHibernate
Couchbase second level Cache provider for NHibernate
QueryBuilder API built on top of NHibernate IQueryOver to enable uses of aliases outside of their scope and bring ease of creating reusable queries.
This project is an NHibernate second-level cache provider for App Fabric. This project is based on the original implementation for the beta versions of AppFabric caching, code named velocity, which can be found at https://github.com/martinernst/NHibernate.Caches/tree/master/Velocity.
A base class for storing settings.
Grapes it is an utility library which takes care of mapping tree-like data structures into database.
Grapes it is an utility library which takes care of mapping tree-like data structures into database.
Helps to manage NHibernate session in a web context
Bootstrap for the Data project: the project that holds actual implementations of your repositories (using NHibernate in this case)
Extends NHibernate's high-low key table to provide indexes per entity. Compatible with Firebird, SQLite, SQL Server 2000-2012, SQL Server CE, Oracle, MySQL and PostgreSQL.
Provides Vertica 7 integration with NHibernate.
Tool to add INotifyPropertyChanged support to NHibernate's proxies, enabling their usage with WPF for example.
Firehawk is a library that helps you to configure NHibernate mapping by code conventions in a fluent and comprehensible way, providing the most standard SQL naming conventions and enabling you to create custom naming conventions.
Adds SQL statements generated by NHibernate to the Glimpse SQL tab.
Query helpers and extensions for NHibernate.
Sample database project for use with LINQPad.NHibernate.FormatSQL in LINQPad.
Seedwork for the Infrastructure Data Application Block - NHibernate
NHibernate Mapping Provider for WrappedSqlFileStream
An OracleManagedDataClientDriver for NHibernate that will track the response times and success rates of your queries as dependencies using Application Insights Telemetry Client