Underscore.js
Underscore is a JavaScript library which provides utility functions for common JavaScript tasks. It is comparable to features provided by Prototype.js and the Ruby language, but opts for a functional programming design instead of extending object prototypes. For example, underscore's _.each function delegates to the host environment's native forEach implementation when present, or a compatible version when absent. The documentation refers to Underscore as "the tie to go along with jQuery's Vorlage:Clarify-span, and Backbone.js's suspenders." Underscore was created by Jeremy Ashkenas, who is also known for Backbone.js and CoffeeScript.[1]
