Wrap constructor in universal module definition

.jshintrc

@@ -17,5 +17,9 @@
   "unused": true,
   "strict": true,
   "trailing": true,
-  "smarttabs": true
+  "smarttabs": true,
+  "globals": {
+    "define": false,
+    "module": false
+  }
 }

dist/echo.js

@@ -1,8 +1,23 @@
-/*! Echo v1.4.0 | (c) 2013 @toddmotto | MIT license | github.com/toddmotto/echo */
-window.Echo = (function (window, document, undefined) {
+/*! Echo v1.4.0 | (c) 2014 @toddmotto | MIT license | github.com/toddmotto/echo */
+(function (name, context, definition) {
 
   'use strict';
 
+  if (typeof define === 'function' && define.amd) {
+    define(definition);
+  }
+  else if (typeof module !== 'undefined' && module.exports) {
+    module.exports = definition();
+  }
+  else {
+    context[name] = definition();
+  }
+})('Echo', this, function() {
+
+  'use strict';
+
+  function Echo() {
+
     var store = [], offset, throttle, poll;
 
     var _inView = function (el) {
@@ -49,4 +64,8 @@ window.Echo = (function (window, document, undefined) {
       render: _throttle
     };
 
-})(window, document);
+  }
+
+  return Echo;
+
+});

dist/echo.min.js

@@ -1,2 +1,2 @@
-/*! Echo v1.4.0 | (c) 2013 @toddmotto | MIT license | github.com/toddmotto/echo */
-window.Echo=function(a,b){"use strict";var c,d,e,f=[],g=function(d){var e=d.getBoundingClientRect();return(e.top>=0&&e.left>=0&&e.top)<=(a.innerHeight||b.documentElement.clientHeight)+parseInt(c)},h=function(){for(var a=f.length;a--;){var b=f[a];g(b)&&(b.src=b.getAttribute("data-echo"),f.splice(a,1))}},i=function(){clearTimeout(e),e=setTimeout(h,d)},j=function(e){var g=b.querySelectorAll("[data-echo]"),h=e||{};c=h.offset||0,d=h.throttle||250;for(var j=0;j<g.length;j++)f.push(g[j]);i(),b.addEventListener?a.addEventListener("scroll",i,!1):a.attachEvent("onscroll",i)};return{init:j,render:i}}(window,document);
+/*! Echo v1.4.0 | (c) 2014 @toddmotto | MIT license | github.com/toddmotto/echo */
+!function(a,b,c){"use strict";"function"==typeof define&&define.amd?define(c):"undefined"!=typeof module&&module.exports?module.exports=c():b[a]=c()}("Echo",this,function(){"use strict";function a(){var a,b,c,d=[],e=function(b){var c=b.getBoundingClientRect();return(c.top>=0&&c.left>=0&&c.top)<=(window.innerHeight||document.documentElement.clientHeight)+parseInt(a)},f=function(){for(var a=d.length;a--;){var b=d[a];e(b)&&(b.src=b.getAttribute("data-echo"),d.splice(a,1))}},g=function(){clearTimeout(c),c=setTimeout(f,b)},h=function(c){var e=document.querySelectorAll("[data-echo]"),f=c||{};a=f.offset||0,b=f.throttle||250;for(var h=0;h<e.length;h++)d.push(e[h]);g(),document.addEventListener?window.addEventListener("scroll",g,!1):window.attachEvent("onscroll",g)};return{init:h,render:g}}return a});

src/echo.js

@@ -1,7 +1,22 @@
-window.Echo = (function (window, document, undefined) {
+(function (name, context, definition) {
 
   'use strict';
 
+  if (typeof define === 'function' && define.amd) {
+    define(definition);
+  }
+  else if (typeof module !== 'undefined' && module.exports) {
+    module.exports = definition();
+  }
+  else {
+    context[name] = definition();
+  }
+})('Echo', this, function() {
+
+  'use strict';
+
+  function Echo() {
+
     var store = [], offset, throttle, poll;
 
     var _inView = function (el) {
@@ -48,4 +63,8 @@ window.Echo = (function (window, document, undefined) {
       render: _throttle
     };
 
-})(window, document);
+  }
+
+  return Echo;
+
+});