Bespoke.js : Bespoke.js is a super minimal, modular presentation library for modern browsers, designed to foster a rich plugin ecosystem.
Photon : UI toolkit for building desktop apps with Electron.
impress.js : It's a presentation framework based on the power of CSS3 transforms and transitions in modern browsers and inspired by the idea behind prezi.com
Moment.js : A javascript date library for parsing, validating, manipulating, and formatting dates.
ClippyJS : Add Clippy or his friends to any website for instant nostalgia.
cssQuery() is a powerful cross-browser JavaScript function that enables querying of a DOM document using CSS selectors. All CSS1 and CSS2 selectors are allowed plus quite a few CSS3 selectors.