This is a multi-level drop down menu that's also a space saver, by stacking the sub menus on top of one another when revealed. CSS3 transforms are used for the transition effect between sub menu changes, though the menu is functional in legacy browsers as well, including IE8+.
Tendina is a super easy-to-use jQuery plugin to rapidly build dropdown side menus.
jQuery Sliding Menu is a mobile-like, list-style, responsive sliding navigation menu.
Slight Submenu is a jQuery plugin that manages behavior of submenus and is highly configurable and extensible.
Pagescroll Menu is ajQuery plugin to create animated scroll menu.
Fixed Nav is a responsive, fixed and touch friendly one page navigation with animated scrolling.
Pikabu is a speedy, flexible framework for off-canvas flyout panels.
Simple markup : Few containers and classes means implementation is a breeze.
Native scrolling: Momentum scrolling in sidebars and smart fallbacks for browsers that don’t support it.
Customization: No theme, just barebones HTML and CSS. Pikabu is customizable to your needs.
Compatibility: It's compatible with many devices.
jQuery Full Screen Nav plugin makes a
<nav> menu overlay the full screen & calculate a size for links on page load and window resize.
Pop Menu is a jQuery plugin to create simple responsive popup menu.
Slidebars is a jQuery plugin for quickly and easily implementing app-style revealing menus and sidebars into your website.
EasyDropDown is a jQuery plugin that effortlessly turns humble
<select> elements into styleable drop-down menus for use in forms or general UI/navigation.
Tocible is a lightweight jQuery plugin for creating table of contents navigation menu.
Shifter is a jQuery plugin for simple slide-out mobile navigation. Shifter works by checking for target elements in the DOM and binding events to them.