Which is not the same thing as node's modules. There's nothing stopping me from making global variables within a module "pattern". Contrast that with a node.js module where even if a variable declaration leaves out a 'var' by accident, the global will not show up in anything that imports that module. I.e., there is no chance of name collisions because each node module gets its own unique and clean global scope.

True, but the question was whether JS had any native ways to support modules, and closures are literally right there. That's a good way to start them. Add more shit on top to make it robust, but they're still there.