NHibernate is a mature, open source object-relational mapper for the .NET framework. It's actively developed, fully featured, and used in thousands of successful projects.
NHibernate is a popular, fast growing ORM with a helpful community of seasoned developers. Used in thousands of commercial and open source projects.
NHibernate Forge, the official new home for the NHibernate community.
http://sourceforge.net/projects/nhibernate/
NHibernate on SourceForge, the source code repository for NHibernate.
Fluent, XML-less, compile safe, automated, convention-based mappings for NHibernate.
The .NET Persistence API, is a persistence and Object Relational Mapping (ORM) specification for the .NET framework.
The specification contains the classes and interfaces that define the contracts between client applications which require persistence and ORM services and the vendors which provide them.
.NET Persistence API is the .NET equivalent for the java JPA framework and is based on it. It offers the same standard for managing relational data in applications using the .NET framework written in C#, Visual Basic and other .NET languages.