Sometimes we need to run our script JS directly from our preferred IDE, even after many of them have evolved their integration with major browsers, there are still those who prefer something more root.
Install Homebrew first:
$ ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)"
$ which brew
Install the V8 engine:
$ brew install v8
Start the V8 console, just run v8!
$ v8 /Users/helmed/cajs/whileLoops/Project/16-whatYoullBuild.js
Tip: To close the terminal, just type quit() and press enter!