DOMPurify - a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify works with a secure default, but offers a lot of configurability and hooks. Demo:
Highly customizable vanilla JS tooltip/popover library
Fast, flexible, and lean implementation of core jQuery designed specifically for the server.
A lightweight, fast, feature-rich, powerful and highly configurable delayed content, image and background lazy loading plugin for jQuery & Zepto.
bind.js - simple two way data binding to HTML and callbacks
Eliminates layout thrashing by batching DOM read/write operations
A tiny tool for easily loading html fragments and templates
zoom in on any element in the DOM
Sieve is a jQuery plugin allows you to quickly add an interactive search filter to any block of content.
Waypoints is a small jQuery plugin that makes it easy to execute a function whenever you scroll to an element.
nicescroll plugin for jquery - scrollbars like iphone/ipad
Scriptable Headless WebKit