nhibernate-core

Used in thousands of projects over many years, offering a stable and reliable ORM solution, as noted in the README's description of being 'fully-featured' and 'actively developed'.

Includes lazy loading, caching support, and transaction management, providing robust tools for optimizing performance and ensuring data integrity, as highlighted in the Key Features.

Supports multiple database systems through configurable dialects, allowing easy switching between databases without major code changes, per the Cross-Database Compatibility feature.

Enables type-safe, compile-time checked queries via a LINQ provider, reducing errors and improving developer productivity, as specified in the Key Features.