# nhibernate/nhibernate-core

NHibernate Object Relational Mapper

Repository: https://github.com/nhibernate/nhibernate-core
Canonical: https://ross.abutalabs.com/products/nhibernate-core
Homepage: https://nhibernate.info
Language: C#
License: LGPL-2.1
License Family: copyleft
Topics: nhibernate, c-sharp, nhibernate-developers, linq, orm, dotnet, dotnet-core, dotnet-core2, object-relational-mapper, criteria-api, linq-provider
Last push: 2026-08-26T17:13:13+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 78, longevity 100
- inputs: {"age_days": 5498, "days_push": 7, "days_rel": 64, "gap_med": 38, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2174, forks 931 (observed 2026-08-28T04:06:22.075183+00:00)

## What it is
NHibernate is a mature, open source object-relational mapper (ORM) for the .NET framework, actively developed and fully featured. It maps regular C# or VB.NET object models to relational databases, supporting inheritance, components, enums, and complex legacy database scenarios.

## Use cases
- map C# domain models to relational database tables
- persist and query objects in a .NET application without writing raw SQL
- generate database schema from domain models
- query entities with LINQ or Criteria API
- work with complex or legacy database schemas from .NET
- manage sessions, transactions, and caching in .NET data access

## When to choose
- you need a mature, fully featured ORM for .NET with strong legacy database support
- you want LINQ and Criteria API querying over mapped entities
- your project needs inheritance, components, and enum mapping without special base classes
- you rely on an established community, extensive documentation, and plugin ecosystem

## When to avoid
- you prefer a lightweight micro-ORM with minimal abstraction like Dapper
- you want an ORM designed primarily for Entity Framework Core conventions and tooling
- you need a non-.NET platform
- your team is unwilling to learn NHibernate's session and mapping model

## Facets
- artifact type: library
- maturity: stable
- function: orm, database, caching, search-engine
- domain: databases, backend, web-development, developer-tools
- platform: dotnet, cross-platform, windows
- tags: object-relational-mapper, linq-provider, criteria-api, nuget, c-sharp, legacy-database-support, code-first-mapping, linux, macos

## Member repositories
- nhibernate/nhibernate-core (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:22.075183+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:48:59.493315+00:00, confidence not recorded.
  - readme: https://github.com/nhibernate/nhibernate-core (fetched 2026-08-28T04:06:22.075183+00:00, sha 9a52d74284f2)
  - homepage: https://nhibernate.info (fetched 2026-08-29T10:29:03.533445+00:00, sha f2dbdb6bf421)
  - site_page: https://nhibernate.info/doc/index.html (fetched 2026-08-29T10:29:03.542263+00:00, sha 5977574f5c8a)
- Data as of 2026-08-30T08:39:29.467469+00:00.