Cypress : JavaScript End to End Testing Framework. Fast, easy and reliable testing for anything that runs in a browser.
Babel : Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.
The HTML5 Shiv : The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari...
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
RequireJS : RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino ...
A JavaScript file you can insert into your pages to simulate the Firebug console in browsers that are not named Firefox.
