Comment by WorldMaker

And NHibernate.Linq and Dapper.Extensions.Linq… Most ORMs in the ecosystem have at least one Linq support library, even if just a third-party extension.

Also, there are fun things that support Linq syntax for non-ORM uses, too, such as System.Reactive.Linq and LanguageExt: https://github.com/louthy/language-ext/wiki/How-to-deal-with...