jQuery Entropizer 是一个简单，轻量级的jQuery插件，使用Entropizer引擎来计算密码强度。它易于使用并提供多个钩子来定制UI。

// Create an Entropizer meter using custom options  $('#meter').entropizer({        // The input field to watch: any selector, DOM element or jQuery instance      // Default: 'input[type=password]:first'      target: '#pwd',        // The event(s) upon which to update the meter UI      // Default: 'keydown keyup'      on: 'keydown',        // Used to calculate the percentage of the bar to fill (see map function below)      // Default: 100      maximum: 80,        // An array of ranges to use when classifying password strength. Used internally by default map      // function and can be used publicly via $.entropizer.classify(value, buckets). Properties      // 'min' and 'max' are used to calculate which bucket to use - upon finding a match, an object      // containing all the other properties is returned, e.g. below, a value of 42 returns      // { message: ':)' }      // Default: 4 ranges with strength and color properties (see source for values)      buckets: [          { max: 40, message: ':(' },          { min: 40, max: 60, message: ':)' },          { min: 60, message: ':D' }      ],        // Either an Entropizer engine options object or an Entropizer instance      // Default: a new Entropizer instance with default settings      engine: {          classes: ['lowercase', 'uppercase', 'numeric']      },        // A callback controlling UI creation - takes a jQuery instance representing the container      // and returns an object containing UI components for access in update and destroy      // Default: creates a track element (the bar background), a bar element and a text element      create: function(container) {          var bar = $('<div>').appendTo(container);          return { foo: bar };      },        // A callback controlling UI cleanup - takes the UI object created by create      // Default: removes the track, bar and text elements      destroy: function(ui) {          ui.foo.remove();      },        // A callback that maps the raw entropy value to an object passed to update. First argument is      // the number of bits of entropy, second argument is an object containing all properties on      // the options object apart from target, on, engine and the callbacks (i.e. by default, just      // maximum and buckets)      // Default: uses maximum and buckets above to return an object with entropy, percent, strength      // and color properties      map: function(entropy, mapOptions) {          return $.extend({ entropy: entropy }, $.entropizer.classify(entropy, mapOptions.buckets));      },        // A callback controlling UI updates - takes the data returned by map and the ui object      // Default: updates the width and background color of the bar, and displays the number of bits      update: function(data, ui) {          ui.foo.text(data.entropy.toFixed(0) + ' ' + data.message);      }  });

项目主页：http://www.open-open.com/lib/view/home/1433230124447