Fixed stupidity.

app/js/main.js

 
 function initialize(DOC){
   console.log(DOC);
-  var canvas = DOC.getElementByID("painter");
+  var canvas = DOC.getElementById("painter");
   if (!canvas){
-    throw new Exception("DOM Missing painter canvas.");
+    throw new Error("DOM Missing painter canvas.");
   }
   var ctx = canvas.getContext("2d");
   if (!ctx){
-    throw new Exception("Failed to obtain canvas context.");
+    throw new Error("Failed to obtain canvas context.");
   }
 }
 
 
 //console.log(document.getElementByID("painter"));
-//initialize(document);
+initialize(document);

index.html

     <canvas id="painte"></canvas>
 
   </body>
-  <script src="app/js/main.js">
-    initialize(document);
-  </script>
+  <script src="app/js/main.js"></script>
 </html>