diff --git a/01-getting-started-with-angular2/src/01-mvc-hello-world/index.html b/01-getting-started-with-angular2/src/01-mvc-hello-world/index.html
index b92115b..5890cdb 100644
--- a/01-getting-started-with-angular2/src/01-mvc-hello-world/index.html
+++ b/01-getting-started-with-angular2/src/01-mvc-hello-world/index.html
@@ -10,11 +10,11 @@
     <link rel="stylesheet" href="https://angular-academy.s3-us-west-1.amazonaws.com/styles/angular-academy-lessons-theme-v1.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/02-template-syntax-properties/index.html b/01-getting-started-with-angular2/src/02-template-syntax-properties/index.html
index aac2fda..56ee0e5 100644
--- a/01-getting-started-with-angular2/src/02-template-syntax-properties/index.html
+++ b/01-getting-started-with-angular2/src/02-template-syntax-properties/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson-2.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/03-template-syntax-interpolation/index.html b/01-getting-started-with-angular2/src/03-template-syntax-interpolation/index.html
index 7d25225..d319291 100644
--- a/01-getting-started-with-angular2/src/03-template-syntax-interpolation/index.html
+++ b/01-getting-started-with-angular2/src/03-template-syntax-interpolation/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/04-template-syntax-events/index.html b/01-getting-started-with-angular2/src/04-template-syntax-events/index.html
index bac162e..c82fc17 100644
--- a/01-getting-started-with-angular2/src/04-template-syntax-events/index.html
+++ b/01-getting-started-with-angular2/src/04-template-syntax-events/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="lesson-4.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/05-template-syntax-components-essentials/index.html b/01-getting-started-with-angular2/src/05-template-syntax-components-essentials/index.html
index eb8c93d..585a7b2 100644
--- a/01-getting-started-with-angular2/src/05-template-syntax-components-essentials/index.html
+++ b/01-getting-started-with-angular2/src/05-template-syntax-components-essentials/index.html
@@ -12,11 +12,11 @@
 
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/components-inputs-and-outputs/index.html b/01-getting-started-with-angular2/src/components-inputs-and-outputs/index.html
index 5d6f9c4..bae18be 100644
--- a/01-getting-started-with-angular2/src/components-inputs-and-outputs/index.html
+++ b/01-getting-started-with-angular2/src/components-inputs-and-outputs/index.html
@@ -10,11 +10,11 @@
     <link rel="stylesheet" href="https://angular-academy.s3-us-west-1.amazonaws.com/styles/angular-academy-lessons-theme-v1.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/core-directives-ng-for/index.html b/01-getting-started-with-angular2/src/core-directives-ng-for/index.html
index eb162bb..061e332 100644
--- a/01-getting-started-with-angular2/src/core-directives-ng-for/index.html
+++ b/01-getting-started-with-angular2/src/core-directives-ng-for/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/core-directives-ngif/index.html b/01-getting-started-with-angular2/src/core-directives-ngif/index.html
index 7c2fed2..132f824 100644
--- a/01-getting-started-with-angular2/src/core-directives-ngif/index.html
+++ b/01-getting-started-with-angular2/src/core-directives-ngif/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/core-directives-ngstyle-ngclass/index.html b/01-getting-started-with-angular2/src/core-directives-ngstyle-ngclass/index.html
index e0724ef..2cc3e00 100644
--- a/01-getting-started-with-angular2/src/core-directives-ngstyle-ngclass/index.html
+++ b/01-getting-started-with-angular2/src/core-directives-ngstyle-ngclass/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/directives-intro/index.html b/01-getting-started-with-angular2/src/directives-intro/index.html
index eaf583d..feda893 100644
--- a/01-getting-started-with-angular2/src/directives-intro/index.html
+++ b/01-getting-started-with-angular2/src/directives-intro/index.html
@@ -12,11 +12,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/directives/index.html b/01-getting-started-with-angular2/src/directives/index.html
index c183f75..4984933 100644
--- a/01-getting-started-with-angular2/src/directives/index.html
+++ b/01-getting-started-with-angular2/src/directives/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/exercise-color-sample/index.html b/01-getting-started-with-angular2/src/exercise-color-sample/index.html
index 07f584a..46044d2 100644
--- a/01-getting-started-with-angular2/src/exercise-color-sample/index.html
+++ b/01-getting-started-with-angular2/src/exercise-color-sample/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/05-template-syntax-components-essentials/lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/forms-model-driven/index.html b/01-getting-started-with-angular2/src/forms-model-driven/index.html
index 67755b7..f7eb3c1 100644
--- a/01-getting-started-with-angular2/src/forms-model-driven/index.html
+++ b/01-getting-started-with-angular2/src/forms-model-driven/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/forms-signup-exercise/index.html b/01-getting-started-with-angular2/src/forms-signup-exercise/index.html
index 67755b7..f7eb3c1 100644
--- a/01-getting-started-with-angular2/src/forms-signup-exercise/index.html
+++ b/01-getting-started-with-angular2/src/forms-signup-exercise/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/forms-template-driven/index.html b/01-getting-started-with-angular2/src/forms-template-driven/index.html
index 16ed1e8..f20649e 100644
--- a/01-getting-started-with-angular2/src/forms-template-driven/index.html
+++ b/01-getting-started-with-angular2/src/forms-template-driven/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/introduction-to-pipes/index.html b/01-getting-started-with-angular2/src/introduction-to-pipes/index.html
index 42766ef..84ecb0e 100644
--- a/01-getting-started-with-angular2/src/introduction-to-pipes/index.html
+++ b/01-getting-started-with-angular2/src/introduction-to-pipes/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="./lesson.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/modules-intro/index.html b/01-getting-started-with-angular2/src/modules-intro/index.html
index b8a03dd..270730e 100644
--- a/01-getting-started-with-angular2/src/modules-intro/index.html
+++ b/01-getting-started-with-angular2/src/modules-intro/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/router-exercise/index.html b/01-getting-started-with-angular2/src/router-exercise/index.html
index e8b5999..255b745 100644
--- a/01-getting-started-with-angular2/src/router-exercise/index.html
+++ b/01-getting-started-with-angular2/src/router-exercise/index.html
@@ -15,11 +15,11 @@
     <link rel="stylesheet" href="/src/router-introduction/router.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/router-introduction/index.html b/01-getting-started-with-angular2/src/router-introduction/index.html
index e1a7484..9421f9b 100644
--- a/01-getting-started-with-angular2/src/router-introduction/index.html
+++ b/01-getting-started-with-angular2/src/router-introduction/index.html
@@ -15,11 +15,11 @@
     <link rel="stylesheet" href="/src/router-introduction/router.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/services-http/index.html b/01-getting-started-with-angular2/src/services-http/index.html
index b3856d6..73a4c74 100644
--- a/01-getting-started-with-angular2/src/services-http/index.html
+++ b/01-getting-started-with-angular2/src/services-http/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/src/services-intro/index.html b/01-getting-started-with-angular2/src/services-intro/index.html
index b3856d6..73a4c74 100644
--- a/01-getting-started-with-angular2/src/services-intro/index.html
+++ b/01-getting-started-with-angular2/src/services-intro/index.html
@@ -11,11 +11,11 @@
     <link rel="stylesheet" href="/src/common-styles/common.css">
 
     <!-- Polyfill(s) for older browsers -->
-    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
+    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
 
-    <script src="https://npmcdn.com/zone.js@0.6.12?main=browser"></script>
-    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
-    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
+    <script src="https://unpkg.com/zone.js@0.6.12?main=browser"></script>
+    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
+    <script src="https://unpkg.com/systemjs@0.19.27/dist/system.src.js"></script>
 
     <script src="/system.config.js"></script>
 
diff --git a/01-getting-started-with-angular2/system.config.js b/01-getting-started-with-angular2/system.config.js
index 6528558..5e805de 100644
--- a/01-getting-started-with-angular2/system.config.js
+++ b/01-getting-started-with-angular2/system.config.js
@@ -6,10 +6,10 @@
         '@angular': '/node_modules/@angular', // sufficient if we didn't pin the version
         '@angular/router': '/node_modules/@angular/router' ,
         '@angular/forms': '/node_modules/@angular/forms',
-        'angular2-in-memory-web-api': 'https://npmcdn.com/angular2-in-memory-web-api', // get latest
-        'rxjs': 'https://npmcdn.com/rxjs@5.0.0-beta.6',
-        'ts': 'https://npmcdn.com/plugin-typescript@4.0.10/lib/plugin.js',
-        'typescript': 'https://npmcdn.com/typescript@1.9.0-dev.20160409/lib/typescript.js',
+        'angular2-in-memory-web-api': 'https://unpkg.com/angular2-in-memory-web-api', // get latest
+        'rxjs': 'https://unpkg.com/rxjs@5.0.0-beta.6',
+        'ts': 'https://unpkg.com/plugin-typescript@4.0.10/lib/plugin.js',
+        'typescript': 'https://unpkg.com/typescript@1.9.0-dev.20160409/lib/typescript.js',
     };
 
     //packages tells the System loader how to load when no filename and/or no extension