• humane.js - A simple, modern, browser notification system.

  • jGrowl - jGrowl is a jQuery plugin that raises unobtrusive messages within the browser, similar to the way that OS X's Growl Framework works.

  • jNotify - The jQuery jNotify plug-in is an unobtrusive notification system for web-based applications. Use jNotify to inform users when specific actions have completed on your siteā€“such as when an AJAX operation complete.

  • smoke.js - A framework-agnostic styled alert system for javascript.

  • jquery-notify - A growl/ubuntu-like notification system written on top of the jQuery-UI widget factory

  • noty - a jQuery plugin to create notifications as an alternative the standard alert dialog

  • alertify.js - An unobtrusive customizable JavaScript notification system

  • sticky - Very small and lightweight notification system, however seems to be unmaintained and abandoned now