LokiJS : A fast, in-memory document-oriented datastore for node.js, browser and cordova
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
SlimerJS : A scriptable browser for Web developers
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 ...
WebTorrent : WebTorrent is a streaming torrent client for the web browser and the desktop.
WebTorrent is written completely in JavaScript – the language of the web...
A JavaScript file you can insert into your pages to simulate the Firebug console in browsers that are not named Firefox.
