diff --git a/src/browser/server/ReactServerRendering.js b/src/browser/server/ReactServerRendering.js
index 02482b17ab03a..670d7524129e8 100644
--- a/src/browser/server/ReactServerRendering.js
+++ b/src/browser/server/ReactServerRendering.js
@@ -23,7 +23,6 @@ var invariant = require('invariant');
 
 /**
  * @param {ReactElement} element
- * @param {?object} context
  * @return {string} the HTML markup
  */
 function renderToString(element) {
@@ -49,7 +48,6 @@ function renderToString(element) {
 
 /**
  * @param {ReactElement} element
- * @param {?object} context
  * @return {string} the HTML markup, without the extra React ID and checksum
  * (for generating static pages)
  */
diff --git a/src/browser/ui/ReactDOMTextComponent.js b/src/browser/ui/ReactDOMTextComponent.js
index e12ee2753a950..4999d750dbffe 100644
--- a/src/browser/ui/ReactDOMTextComponent.js
+++ b/src/browser/ui/ReactDOMTextComponent.js
@@ -43,7 +43,7 @@ var ReactDOMTextComponent = function(props) {
 assign(ReactDOMTextComponent.prototype, {
 
   /**
-   * @param {ReactText} node
+   * @param {ReactText} text
    * @internal
    */
   construct: function(text) {
diff --git a/src/browser/ui/__tests__/ReactDOMTextComponent-test.js b/src/browser/ui/__tests__/ReactDOMTextComponent-test.js
index 269eb0ac6952e..37a1b9822b5bf 100644
--- a/src/browser/ui/__tests__/ReactDOMTextComponent-test.js
+++ b/src/browser/ui/__tests__/ReactDOMTextComponent-test.js
@@ -36,7 +36,7 @@ describe('ReactDOMTextComponent', function() {
     expect(foo.tagName).toBe('SPAN');
     expect(bar.tagName).toBe('SPAN');
 
-    var inst = React.render(<div>{'baz'}{'qux'}</div>, el);
+    inst = React.render(<div>{'baz'}{'qux'}</div>, el);
     // After the update, the spans should have stayed in place (as opposed to
     // getting unmounted and remounted)
     expect(inst.getDOMNode().children[0]).toBe(foo);
diff --git a/src/browser/ui/dom/components/__tests__/ReactDOMSelect-test.js b/src/browser/ui/dom/components/__tests__/ReactDOMSelect-test.js
index 7aca652a2f4a4..4f99f99bf9788 100644
--- a/src/browser/ui/dom/components/__tests__/ReactDOMSelect-test.js
+++ b/src/browser/ui/dom/components/__tests__/ReactDOMSelect-test.js
@@ -138,9 +138,7 @@ describe('ReactDOMSelect', function() {
   });
 
   it('should reset child options selected when they are changed and `value` is set', function() {
-    var stub =
-      <select multiple={true} value={["a", "b"]}>
-      </select>
+    var stub = <select multiple={true} value={["a", "b"]} />;
     stub = ReactTestUtils.renderIntoDocument(stub);
 
     stub.setProps({
@@ -149,9 +147,9 @@ describe('ReactDOMSelect', function() {
         <option value="b">b</option>,
         <option value="c">c</option>
       ]
-    })
+    });
 
-    var node = stub.getDOMNode()
+    var node = stub.getDOMNode();
 
     expect(node.options[0].selected).toBe(true);  // a
     expect(node.options[1].selected).toBe(true);  // b
diff --git a/src/core/ReactComponent.js b/src/core/ReactComponent.js
index aefed025e4294..678aa7033349b 100644
--- a/src/core/ReactComponent.js
+++ b/src/core/ReactComponent.js
@@ -180,7 +180,7 @@ var ReactComponent = {
       invariant(
         false,
         'getPublicInstance should never be called on the base class. It must ' +
-        'be overriden.'
+        'be overridden.'
       );
     }
   }
diff --git a/src/core/ReactCompositeComponent.js b/src/core/ReactCompositeComponent.js
index a65efe7c2ef1b..fed6166db5490 100644
--- a/src/core/ReactCompositeComponent.js
+++ b/src/core/ReactCompositeComponent.js
@@ -21,12 +21,10 @@ var ReactPerf = require('ReactPerf');
 var ReactPropTypeLocations = require('ReactPropTypeLocations');
 var ReactUpdates = require('ReactUpdates');
 
-var emptyObject = require('emptyObject');
 var assign = require('Object.assign');
 var emptyObject = require('emptyObject');
 var invariant = require('invariant');
 var keyMirror = require('keyMirror');
-var monitorCodeUse = require('monitorCodeUse');
 var shouldUpdateReactComponent = require('shouldUpdateReactComponent');
 var warning = require('warning');
 
@@ -428,7 +426,9 @@ var ReactCompositeComponentMixin = assign({},
   _processContext: function(context) {
     var maskedContext = null;
     var contextTypes = this._instance.constructor.contextTypes;
-    if (!contextTypes) return emptyObject;
+    if (!contextTypes) {
+      return emptyObject;
+    }
     maskedContext = {};
     for (var contextName in contextTypes) {
       maskedContext[contextName] = context[contextName];
diff --git a/src/core/ReactPropTransferer.js b/src/core/ReactPropTransferer.js
index b1a3c3d549653..6b9edc364ec2c 100644
--- a/src/core/ReactPropTransferer.js
+++ b/src/core/ReactPropTransferer.js
@@ -13,11 +13,7 @@
 
 var assign = require('Object.assign');
 var emptyFunction = require('emptyFunction');
-var invariant = require('invariant');
 var joinClasses = require('joinClasses');
-var warning = require('warning');
-
-var didWarn = false;
 
 /**
  * Creates a transfer strategy that will merge prop values using the supplied
diff --git a/src/core/ReactRef.js b/src/core/ReactRef.js
index b93290703ef3d..d99a91a4cc9e0 100644
--- a/src/core/ReactRef.js
+++ b/src/core/ReactRef.js
@@ -1,17 +1,10 @@
 /**
- * Copyright 2013-2014 Facebook, Inc.
+ * Copyright 2013-2014, Facebook, Inc.
+ * All rights reserved.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
  *
  * @providesModule ReactRef
  */
diff --git a/src/core/__tests__/ReactEmptyComponent-test.js b/src/core/__tests__/ReactEmptyComponent-test.js
index 8236db353952b..9882de9e60481 100644
--- a/src/core/__tests__/ReactEmptyComponent-test.js
+++ b/src/core/__tests__/ReactEmptyComponent-test.js
@@ -232,4 +232,3 @@ describe('ReactEmptyComponent', function() {
     );
   });
 });
-
diff --git a/src/core/instantiateReactComponent.js b/src/core/instantiateReactComponent.js
index 593f54c432f8b..36fef60f55c43 100644
--- a/src/core/instantiateReactComponent.js
+++ b/src/core/instantiateReactComponent.js
@@ -101,7 +101,8 @@ function instantiateReactComponent(node, parentCompositeType) {
   } else {
     invariant(
       false,
-      'Encountered invalid React node of type ' + typeof node
+      'Encountered invalid React node of type %s',
+      typeof node
     );
   }
 
diff --git a/src/core/shouldUpdateReactComponent.js b/src/core/shouldUpdateReactComponent.js
index 10c39d9c652e0..90bfd6375e9f6 100644
--- a/src/core/shouldUpdateReactComponent.js
+++ b/src/core/shouldUpdateReactComponent.js
@@ -12,8 +12,6 @@
 
 "use strict";
 
-var ReactNativeComponent = require('ReactNativeComponent');
-
 /**
  * Given a `prevElement` and `nextElement`, determines if the existing
  * instance should be updated as opposed to being destroyed or replaced by a new
diff --git a/src/test/ReactTestUtils.js b/src/test/ReactTestUtils.js
index 8871a8c12ca29..fec6709b538e3 100644
--- a/src/test/ReactTestUtils.js
+++ b/src/test/ReactTestUtils.js
@@ -25,7 +25,6 @@ var ReactUpdates = require('ReactUpdates');
 var SyntheticEvent = require('SyntheticEvent');
 
 var assign = require('Object.assign');
-var instantiateReactComponent = require('instantiateReactComponent');
 
 var topLevelTypes = EventConstants.topLevelTypes;