Any of the otherlang-linq projects miss the forest for the trees, the whole point of LINQ is that it's not a set of chain-able methods on IEnumerable - providers get access to the expression tree and can use them to do all sorts of crazy things (see: EntityFramework, Linq2Sql).

I love Kotlin and I don't really get a hankering for LINQ when I'm using it, but I wish people would stop trying to say "but we can do that too!" when they really can't.