jQuery
jQuery JavaScript library
...With a combination of versatility and extensibility, jQuery has changed the way that millions of people write JavaScript. jQuery also supports Node, browser extensions, and other non-browser environments. To build jQuery, you need to have the latest Node.js/npm and git 1.7 or later. Earlier versions might work, but are not supported. Special builds can be created that exclude subsets of jQuery functionality. This allows for smaller custom builds when the builder is certain that those parts of jQuery are not being used. For example, an app that only used JSONP for $.ajax() and did not need to calculate offsets or positions of elements could exclude the offset and ajax/xhr modules.