Don't try to emulate __proto__, just rewrite Z method for IE

src/ie.js

@@ -2,25 +2,18 @@
 //     (c) 2010-2013 Thomas Fuchs
 //     Zepto.js may be freely distributed under the MIT license.
 
-// this provides a incomplete but workable implementation of
-// __proto__, which enables Zepto to run on Internet Explorer <= 10
 ;(function(){
+  // __proto__ doesn't exist on IE<11, so redefine
+  // the Z function to use object extension instead
   if (!('__proto__' in {})) {
-    Object.defineProperty(Object.prototype, '__proto__', {
-      set: function(newPrototype) {
-        for (var property in newPrototype) {
-          // stops stack overflow errors
-          if (property == '__proto__') continue
-
-          this[property] = newPrototype[property]
-        }
-      },
-      get: function() {
-        return this
-      },
-      enumerable: false,
-      configurable: true
-    });
+    $.extend($.zepto, {
+      Z: function(dom, selector) {
+        dom = dom || []
+        $.extend(dom, $.fn)
+        dom.selector = selector || ''
+        return dom
+      }
+    })
   }
 
   // getComputedStyle shouldn't freak out when called