License: MIT and GPL licenses
Home Page: http://arshaw.com/fullcalendar/
Author: Adam Shaw
FullCalendar is a jQuery plugin that provides a full-sized, drag & drop calendar like the one below. It uses AJAX to fetch events on-the-fly for each month and is easily configured to use your own feed format (an extension is provided for Google Calendar). It is visually customizable and exposes hooks for user-triggered events (like clicking or dragging an event). It is open source and dual licensed under the MIT or GPL Version 2 licenses.
<link rel="stylesheet" type="text/css" href="jquery.fullcalendar.css" />