eev.js

var Eev = (function () {
  var id = 0;
  var splitter = /[\s,]+/g;

  // A relatively generic LinkedList impl
  function LinkedList(linkConstructor) {
    this.head = new RunnableLink();
    this.tail = new RunnableLink(this.head);
    this.head.next = this.tail;
    this.linkConstructor = linkConstructor;
    this.reg = {};
  }

  LinkedList.prototype = {
    insert: function (data) {
      var link = new RunnableLink(this.tail.prev, this.tail, data);
      link.next.prev = link.prev.next = link;
      return link;
    },

    remove: function (link) {
      link.prev.next = link.next;
      link.next.prev = link.prev;
    }
  };

  // A link in the linked list which allows
  // for efficient execution of the callbacks
  function RunnableLink(prev, next, fn) {
    this.prev = prev;
    this.next = next;
    this.fn = fn || noop;
  }

  RunnableLink.prototype.run = function (data) {
    this.fn(data);
    this.next && this.next.run(data);
  };

  function noop () { }

  function Eev () {
    this.events = {};
  }

  Eev.prototype = {
    constructor: Eev,

    on: function (names, fn) {
      var me = this;

      names.split(splitter).forEach(function (name) {
        var list = me.events[name] || (me.events[name] = new LinkedList());
        var eev = fn._eev || (fn._eev = (++id));

        list.reg[eev] || (list.reg[eev] = list.insert(fn));
      });
    },

    off: function (names, fn) {
      var me = this;
      fn && names.split(splitter).forEach(function (name) {
        var list = me.events[name];

        if (!list) {
          return;
        }

        var link = list.reg[fn._eev];

        list.reg[fn._eev] = undefined;

        list && link && list.remove(link);
      });
    },

    emit: function (name, data) {
      var evt = this.events[name];
      evt && evt.head.run(data);
    }
  };

  return Eev;
}());

// AMD/CommonJS support
(function (root, factory) {
  var define = root.define;

  if (define && define.amd) {
    define([], factory);
  } else if (typeof module !== 'undefined' && module.exports) {
    module.exports = factory();
  }
}(this, function () { return Eev; }));