diff --git a/examples/Interactive Widgets/Custom Widget - Hello World.ipynb b/examples/Interactive Widgets/Custom Widget - Hello World.ipynb
index 6fa8784..f28119f 100644
--- a/examples/Interactive Widgets/Custom Widget - Hello World.ipynb
+++ b/examples/Interactive Widgets/Custom Widget - Hello World.ipynb
@@ -2,7 +2,7 @@
  "metadata": {
   "celltoolbar": "Slideshow",
   "name": "",
-  "signature": "sha256:9763f005a69fc65b7a7977011d9604b09b4959e7293cbbb2cf35cc482380e671"
+  "signature": "sha256:a53951979397cd38785846c18854053eaa5093f6f08246dbcce76b7d243e2153"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -128,7 +128,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 2
+     "prompt_number": 1
     },
     {
      "cell_type": "heading",
@@ -272,7 +272,7 @@
        ]
       }
      ],
-     "prompt_number": 3
+     "prompt_number": 2
     },
     {
      "cell_type": "heading",
@@ -334,7 +334,7 @@
        ]
       }
      ],
-     "prompt_number": 2
+     "prompt_number": 3
     },
     {
      "cell_type": "heading",
@@ -400,7 +400,7 @@
        ]
       }
      ],
-     "prompt_number": 5
+     "prompt_number": 4
     },
     {
      "cell_type": "heading",
@@ -430,7 +430,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 6
+     "prompt_number": 5
     },
     {
      "cell_type": "heading",
@@ -461,19 +461,8 @@
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [
-      {
-       "ename": "NameError",
-       "evalue": "name 'widgets' is not defined",
-       "output_type": "pyerr",
-       "traceback": [
-        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
-        "\u001b[0;32m<ipython-input-5-18ff342e181d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mclass\u001b[0m \u001b[0mHelloWidget\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mwidgets\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mDOMWidget\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      2\u001b[0m     \u001b[0m_view_name\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mUnicode\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'HelloView'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0msync\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mTrue\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      3\u001b[0m     \u001b[0mvalue\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mUnicode\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'Hello World!'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0msync\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mTrue\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-        "\u001b[0;31mNameError\u001b[0m: name 'widgets' is not defined"
-       ]
-      }
-     ],
-     "prompt_number": 5
+     "outputs": [],
+     "prompt_number": 6
     },
     {
      "cell_type": "heading",
@@ -556,7 +545,7 @@
        ]
       }
      ],
-     "prompt_number": 6
+     "prompt_number": 7
     },
     {
      "cell_type": "heading",
@@ -632,7 +621,7 @@
        ]
       }
      ],
-     "prompt_number": 9
+     "prompt_number": 8
     },
     {
      "cell_type": "heading",
@@ -656,7 +645,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 10
+     "prompt_number": 9
     },
     {
      "cell_type": "code",
@@ -667,7 +656,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 11
+     "prompt_number": 10
     },
     {
      "cell_type": "heading",
@@ -727,7 +716,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 12
+     "prompt_number": 11
     },
     {
      "cell_type": "heading",
@@ -817,7 +806,7 @@
        ]
       }
      ],
-     "prompt_number": 13
+     "prompt_number": 12
     },
     {
      "cell_type": "heading",
@@ -927,7 +916,7 @@
        ]
       }
      ],
-     "prompt_number": 14
+     "prompt_number": 13
     },
     {
      "cell_type": "heading",
diff --git a/examples/Interactive Widgets/Widget Basics.ipynb b/examples/Interactive Widgets/Widget Basics.ipynb
index 443b7e6..cccec87 100644
--- a/examples/Interactive Widgets/Widget Basics.ipynb
+++ b/examples/Interactive Widgets/Widget Basics.ipynb
@@ -2,7 +2,7 @@
  "metadata": {
   "celltoolbar": "Slideshow",
   "name": "",
-  "signature": "sha256:f6c1dd624d35ab0c768f77dffdae914baf4d88a3c244047c00ffca8b9c96e81e"
+  "signature": "sha256:b8ade017615ae4e656f0740a85c77764ff451dd651110af0b5dc92fd5cb409ff"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -261,6 +261,18 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
+      "w = IntSliderWidget()\n",
+      "display(w)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
       "w.value"
      ],
      "language": "python",
@@ -269,13 +281,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 6,
+       "prompt_number": 11,
        "text": [
-        "0"
+        "40"
        ]
       }
      ],
-     "prompt_number": 6
+     "prompt_number": 11
     },
     {
      "cell_type": "markdown",
@@ -293,7 +305,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 7
+     "prompt_number": 12
     },
     {
      "cell_type": "heading",
@@ -326,7 +338,7 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 8,
+       "prompt_number": 13,
        "text": [
         "['_view_name',\n",
         " 'orientation',\n",
@@ -343,7 +355,7 @@
        ]
       }
      ],
-     "prompt_number": 8
+     "prompt_number": 13
     },
     {
      "cell_type": "heading",
@@ -373,7 +385,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 9
+     "prompt_number": 14
     },
     {
      "cell_type": "heading",
@@ -410,7 +422,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 10
+     "prompt_number": 15
     },
     {
      "cell_type": "heading",
@@ -440,7 +452,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 11
+     "prompt_number": 16
     },
     {
      "cell_type": "markdown",
diff --git a/examples/Interactive Widgets/Widget Events.ipynb b/examples/Interactive Widgets/Widget Events.ipynb
index be6d184..0a23868 100644
--- a/examples/Interactive Widgets/Widget Events.ipynb
+++ b/examples/Interactive Widgets/Widget Events.ipynb
@@ -8,7 +8,7 @@
   ],
   "celltoolbar": "Slideshow",
   "name": "",
-  "signature": "sha256:ac1b90929c7736b2261ba498b6f28dd89d3e7b7981c43f937879febe6841e4cd"
+  "signature": "sha256:00bfd86bbcdbb8dcaea27753885c4ee4727c9b56bd460c3ee0595641e4afe21f"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -122,7 +122,29 @@
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Button clicked.\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Button clicked.\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Button clicked.\n"
+       ]
+      }
+     ],
      "prompt_number": 3
     },
     {
@@ -158,7 +180,15 @@
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "adsfasdf\n"
+       ]
+      }
+     ],
      "prompt_number": 4
     },
     {
@@ -262,7 +292,50 @@
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "1\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "4\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "13\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "26\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "31\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "34\n"
+       ]
+      }
+     ],
      "prompt_number": 6
     },
     {
diff --git a/examples/Interactive Widgets/Widget List.ipynb b/examples/Interactive Widgets/Widget List.ipynb
index 4d22d19..fcfc2ea 100644
--- a/examples/Interactive Widgets/Widget List.ipynb
+++ b/examples/Interactive Widgets/Widget List.ipynb
@@ -2,7 +2,7 @@
  "metadata": {
   "celltoolbar": "Slideshow",
   "name": "",
-  "signature": "sha256:4200cc7b2c7067f4c5391eeee6ba0d9be43b4faa16a245ba1634e7de66150372"
+  "signature": "sha256:5ded7796417476da43feb6a52919043719f504bd72c145163e3e8a1105c5b642"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -612,7 +612,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 20
+     "prompt_number": 19
     },
     {
      "cell_type": "heading",
@@ -635,7 +635,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 21
+     "prompt_number": 20
     },
     {
      "cell_type": "markdown",
diff --git a/examples/Interactive Widgets/Widget Styling.ipynb b/examples/Interactive Widgets/Widget Styling.ipynb
index d8f7756..586c09e 100644
--- a/examples/Interactive Widgets/Widget Styling.ipynb
+++ b/examples/Interactive Widgets/Widget Styling.ipynb
@@ -8,7 +8,7 @@
   ],
   "celltoolbar": "Slideshow",
   "name": "",
-  "signature": "sha256:6ee07cf9871c5a2431610eb8a2a5057f9e669769932696690f70967b255fbea7"
+  "signature": "sha256:ea0c2f71869ec3d5fb1b007e1f13023fa5fc580ad7bee737d5cbbce8a1490169"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -55,7 +55,7 @@
        ]
       }
      ],
-     "prompt_number": 6
+     "prompt_number": 1
     },
     {
      "cell_type": "heading",
@@ -89,14 +89,14 @@
      "collapsed": false,
      "input": [
       "from IPython.html import widgets\n",
-      "text = widgets.TextWidget()\n",
+      "text = widgets.TextWidget(value=\"Hello World!\")\n",
       "text.set_css('background', 'lime')\n",
       "text "
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 7
+     "prompt_number": 5
     },
     {
      "cell_type": "heading",
@@ -126,7 +126,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 8
+     "prompt_number": 6
     },
     {
      "cell_type": "heading",
@@ -156,7 +156,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 9
+     "prompt_number": 7
     },
     {
      "cell_type": "heading",
@@ -192,7 +192,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 12
+     "prompt_number": 8
     },
     {
      "cell_type": "heading",
@@ -222,7 +222,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 13
+     "prompt_number": 9
     },
     {
      "cell_type": "markdown",
@@ -269,7 +269,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 14
+     "prompt_number": 10
     },
     {
      "cell_type": "heading",
@@ -304,7 +304,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 15
+     "prompt_number": 11
     },
     {
      "cell_type": "heading",
@@ -354,7 +354,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 16
+     "prompt_number": 12
     },
     {
      "cell_type": "heading",
@@ -389,7 +389,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 17
+     "prompt_number": 13
     },
     {
      "cell_type": "heading",
@@ -421,7 +421,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 18
+     "prompt_number": 14
     },
     {
      "cell_type": "code",
@@ -432,7 +432,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -441,7 +441,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -450,7 +450,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -459,7 +459,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -468,7 +468,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -477,7 +477,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -486,7 +486,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -495,7 +495,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -504,7 +504,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -513,7 +513,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -522,7 +522,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -531,7 +531,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -540,7 +540,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -549,7 +549,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -558,7 +558,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 19
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -569,7 +569,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 20
+     "prompt_number": 16
     },
     {
      "cell_type": "code",
@@ -580,7 +580,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 21
+     "prompt_number": 17
     },
     {
      "cell_type": "heading",
@@ -614,7 +614,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 22
+     "prompt_number": 18
     },
     {
      "cell_type": "markdown",
@@ -639,7 +639,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 23
+     "prompt_number": 19
     },
     {
      "cell_type": "markdown",
@@ -664,7 +664,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 24
+     "prompt_number": 20
     },
     {
      "cell_type": "heading",
@@ -733,7 +733,7 @@
        ]
       }
      ],
-     "prompt_number": 25
+     "prompt_number": 21
     },
     {
      "cell_type": "code",
@@ -752,7 +752,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 26
+     "prompt_number": 22
     },
     {
      "cell_type": "code",
@@ -766,7 +766,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 27
+     "prompt_number": 23
     },
     {
      "cell_type": "code",
@@ -780,7 +780,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 28
+     "prompt_number": 24
     },
     {
      "cell_type": "heading",
@@ -1164,7 +1164,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 29
+     "prompt_number": 25
     },
     {
      "cell_type": "heading",
@@ -1197,7 +1197,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 30
+     "prompt_number": 26
     },
     {
      "cell_type": "markdown",
@@ -1216,7 +1216,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 31
+     "prompt_number": 27
     },
     {
      "cell_type": "heading",
@@ -1273,7 +1273,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 32
+     "prompt_number": 28
     },
     {
      "cell_type": "heading",
@@ -1307,7 +1307,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 33
+     "prompt_number": 29
     },
     {
      "cell_type": "heading",
@@ -1326,27 +1326,27 @@
      "collapsed": false,
      "input": [
       "classes = [\n",
-      "    'progress-bar-info', \n",
-      "    'progress-bar-success', \n",
-      "    'progress-bar-warning', \n",
-      "    'progress-bar-danger',\n",
-      "    'progress-bar-info progress-striped', \n",
-      "    'progress-bar-success progress-striped', \n",
-      "    'progress-bar-warning progress-striped', \n",
-      "    'progress-bar-danger progress-striped',\n",
-      "    'active progress-bar-info progress-striped', \n",
-      "    'active progress-bar-success progress-striped', \n",
-      "    'active progress-bar-warning progress-striped', \n",
-      "    'active progress-bar-danger progress-striped',\n",
+      "    'progress-info', \n",
+      "    'progress-success', \n",
+      "    'progress-warning', \n",
+      "    'progress-danger',\n",
+      "    'progress-info progress-striped', \n",
+      "    'progress-success progress-striped', \n",
+      "    'progress-warning progress-striped', \n",
+      "    'progress-danger progress-striped',\n",
+      "    'active progress-info progress-striped', \n",
+      "    'active progress-success progress-striped', \n",
+      "    'active progress-warning progress-striped', \n",
+      "    'active progress-danger progress-striped',\n",
       "]\n",
       "ws = [widgets.IntProgressWidget(value=50, description=c) for c in classes]\n",
       "ret = [display(w) for w in ws]\n",
-      "ret = [ws[i].add_class(c, selector=\"\" if c == \"progress-striped\" or c == \"active\" else \".progress-bar\") for i, cs in enumerate(classes) for c in cs.split(' ')]"
+      "ret = [ws[i].add_class(c) for i, cs in enumerate(classes) for c in cs.split(' ')]"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 48
+     "prompt_number": 31
     },
     {
      "cell_type": "heading",
@@ -1378,7 +1378,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 49
+     "prompt_number": 32
     },
     {
      "cell_type": "code",
@@ -1389,7 +1389,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 50
+     "prompt_number": 33
     },
     {
      "cell_type": "code",
@@ -1400,7 +1400,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 51
+     "prompt_number": 34
     },
     {
      "cell_type": "heading",
@@ -1449,7 +1449,7 @@
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 52
+     "prompt_number": 35
     },
     {
      "cell_type": "markdown",