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...
IE7.js : IE7.js is a JavaScript library to make Microsoft Internet Explorer behave like a standards-compliant browser. It fixes many HTML and CSS issues and ma...
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
LokiJS : A fast, in-memory document-oriented datastore for node.js, browser and cordova
A JavaScript file you can insert into your pages to simulate the Firebug console in browsers that are not named Firefox.