io.js vs. Aura vs. Cocoa (OS X)

io.js is a JavaScript platform built on Chrome's V8 runtime. This project began as a fork of Joyent's Node.js and is compatible with the npm ecosystem.

The Aura project centers around a collection of high-quality, well-tested, semantically versioned, standards-compliant, independent library packages that can be used in any codebase.

Much of Cocoa is implemented in Objective-C, an object-oriented language that is compiled to run at incredible speed, yet employs a truly dynamic runtime making it uniquely flexible. Because Objective-C is a superset of C, it is easy to mix C and even C++ into your Cocoa applications.