LINQ API Clarifications

Question

I know Microsoft Implementation of LINQ.Are Different LINQ APIs availabe (third party)?

Answer 1

Yes:

LINQ to Twitter

LINQ to Excel

LINQ To Everything Else

Answer 2

There are certainly different LINQ providers around. For example, there's LINQ to NHibernate; I have Push LINQ; there's a .NET 2.0-compatible port of LINQ to Objects, and various others.

One of the nice things about LINQ is that it's more of a pattern than anything else. You can implement the bits of the pattern that are useful to you, in whatever way you want. If you want an out-of-process query engine then you can use Queryable to start with, but you don't have to use either IEnumerable<T> or IQueryable<T>.