Zepto.js
JavaScript library for modern browsers with a jQuery compatible API
...-friendly MIT license. Note that some optional features of Zepto specifically target mobile browsers; as the original project goal was to specifically provide a leaner alternative to jQuery for the mobile web. Zepto is a good choice for browser extensions (for Safari, Chrome and Firefox) and to develop HTML-based views within native app frameworks, such as PhoneGap. In short, Zepto is expected to work in every modern browser and browser-like environment.