c# - IQueryable vs IQueryable<T>

Question

I'm simply wondering why there is a IQueryable<T> version without the generic capability ?

Answer 1

The generic IQueryable<T> is the one you use most often in method signatures and the like. The non-generic IQueryable exist primarily to give you a weakly typed entry point primarily for dynamic query building scenarios.

by Matt Warren from LINQ: Building an IQueryable Provider - Part I

You should use generic IQueryable<T> everywhere it's possible.