diff --git a/LICENSE.txt b/LICENSE.txt
index 17764328c..9cd87e5dc 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,5 +1,5 @@
 Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
-Based on Underscore.js 1.7.0, copyright 2009-2015 Jeremy Ashkenas,
+Based on Underscore.js, copyright 2009-2015 Jeremy Ashkenas,
 DocumentCloud and Investigative Reporters & Editors <http://underscorejs.org/>
 
 Permission is hereby granted, free of charge, to any person obtaining
diff --git a/README.md b/README.md
index 29fa3b35e..5a4b3c627 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# lodash-es v3.3.1
+# lodash-es v3.4.0
 
 The [modern build](https://github.com/lodash/lodash/wiki/Build-Differences) of [lodash](https://lodash.com/) exported as [ES](https://people.mozilla.org/~jorendorff/es6-draft.html) modules.
 
@@ -7,4 +7,4 @@ Generated using [lodash-cli](https://www.npmjs.com/package/lodash-cli):
 $ lodash modularize modern exports=es -o ./
 ```
 
-See the [package source](https://github.com/lodash/lodash/tree/3.3.1-es) for more details.
+See the [package source](https://github.com/lodash/lodash/tree/3.4.0-es) for more details.
diff --git a/array/difference.js b/array/difference.js
index 085893756..627919db3 100644
--- a/array/difference.js
+++ b/array/difference.js
@@ -24,16 +24,17 @@ import isArray from '../lang/isArray';
  * // => [1, 3]
  */
 function difference() {
-  var index = -1,
-      length = arguments.length;
+  var args = arguments,
+      index = -1,
+      length = args.length;
 
   while (++index < length) {
-    var value = arguments[index];
+    var value = args[index];
     if (isArray(value) || isArguments(value)) {
       break;
     }
   }
-  return baseDifference(value, baseFlatten(arguments, false, true, ++index));
+  return baseDifference(value, baseFlatten(args, false, true, ++index));
 }
 
 export default difference;
diff --git a/array/dropRightWhile.js b/array/dropRightWhile.js
index 7c2a13f94..91c94728e 100644
--- a/array/dropRightWhile.js
+++ b/array/dropRightWhile.js
@@ -39,7 +39,7 @@ import baseSlice from '../internal/baseSlice';
  * ];
  *
  * // using the `_.matches` callback shorthand
- * _.pluck(_.dropRightWhile(users, { 'user': pebbles, 'active': false }), 'user');
+ * _.pluck(_.dropRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user');
  * // => ['barney', 'fred']
  *
  * // using the `_.matchesProperty` callback shorthand
diff --git a/array/findLastIndex.js b/array/findLastIndex.js
index 1606833e9..ce91f93b9 100644
--- a/array/findLastIndex.js
+++ b/array/findLastIndex.js
@@ -42,7 +42,7 @@ import baseCallback from '../internal/baseCallback';
  *
  * // using the `_.matchesProperty` callback shorthand
  * _.findLastIndex(users, 'active', false);
- * // => 1
+ * // => 2
  *
  * // using the `_.property` callback shorthand
  * _.findLastIndex(users, 'active');
diff --git a/array/flatten.js b/array/flatten.js
index f50aee565..b22b17ee5 100644
--- a/array/flatten.js
+++ b/array/flatten.js
@@ -26,7 +26,7 @@ function flatten(array, isDeep, guard) {
   if (guard && isIterateeCall(array, isDeep, guard)) {
     isDeep = false;
   }
-  return length ? baseFlatten(array, isDeep) : [];
+  return length ? baseFlatten(array, isDeep, false, 0) : [];
 }
 
 export default flatten;
diff --git a/array/flattenDeep.js b/array/flattenDeep.js
index 383ed3710..0bbd95cdb 100644
--- a/array/flattenDeep.js
+++ b/array/flattenDeep.js
@@ -15,7 +15,7 @@ import baseFlatten from '../internal/baseFlatten';
  */
 function flattenDeep(array) {
   var length = array ? array.length : 0;
-  return length ? baseFlatten(array, true) : [];
+  return length ? baseFlatten(array, true, false, 0) : [];
 }
 
 export default flattenDeep;
diff --git a/array/indexOf.js b/array/indexOf.js
index d08de53db..a92895fb4 100644
--- a/array/indexOf.js
+++ b/array/indexOf.js
@@ -42,14 +42,14 @@ function indexOf(array, value, fromIndex) {
     return -1;
   }
   if (typeof fromIndex == 'number') {
-    fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0);
+    fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : fromIndex;
   } else if (fromIndex) {
     var index = binaryIndex(array, value),
         other = array[index];
 
     return (value === value ? value === other : other !== other) ? index : -1;
   }
-  return baseIndexOf(array, value, fromIndex);
+  return baseIndexOf(array, value, fromIndex || 0);
 }
 
 export default indexOf;
diff --git a/array/intersection.js b/array/intersection.js
index 4b115a5bb..e204f130a 100644
--- a/array/intersection.js
+++ b/array/intersection.js
@@ -47,11 +47,11 @@ function intersection() {
   outer:
   while (++index < length) {
     value = array[index];
-    if ((seen ? cacheIndexOf(seen, value) : indexOf(result, value)) < 0) {
+    if ((seen ? cacheIndexOf(seen, value) : indexOf(result, value, 0)) < 0) {
       argsIndex = argsLength;
       while (--argsIndex) {
         var cache = caches[argsIndex];
-        if ((cache ? cacheIndexOf(cache, value) : indexOf(args[argsIndex], value)) < 0) {
+        if ((cache ? cacheIndexOf(cache, value) : indexOf(args[argsIndex], value, 0)) < 0) {
           continue outer;
         }
       }
diff --git a/array/pull.js b/array/pull.js
index bab5eb17e..d911ba079 100644
--- a/array/pull.js
+++ b/array/pull.js
@@ -31,17 +31,19 @@ var splice = arrayProto.splice;
  * // => [1, 1]
  */
 function pull() {
-  var array = arguments[0];
+  var args = arguments,
+      array = args[0];
+
   if (!(array && array.length)) {
     return array;
   }
   var index = 0,
       indexOf = baseIndexOf,
-      length = arguments.length;
+      length = args.length;
 
   while (++index < length) {
     var fromIndex = 0,
-        value = arguments[index];
+        value = args[index];
 
     while ((fromIndex = indexOf(array, value, fromIndex)) > -1) {
       splice.call(array, fromIndex, 1);
diff --git a/array/union.js b/array/union.js
index 43b2d69b8..4eeeff37e 100644
--- a/array/union.js
+++ b/array/union.js
@@ -21,7 +21,7 @@ import baseUniq from '../internal/baseUniq';
  * // => [1, 2, 4]
  */
 function union() {
-  return baseUniq(baseFlatten(arguments, false, true));
+  return baseUniq(baseFlatten(arguments, false, true, 0));
 }
 
 export default union;
diff --git a/chain/lodash.js b/chain/lodash.js
index c94be2104..31ccb31eb 100644
--- a/chain/lodash.js
+++ b/chain/lodash.js
@@ -49,26 +49,26 @@ var hasOwnProperty = objectProto.hasOwnProperty;
  * `mixin`, `negate`, `noop`, `omit`, `once`, `pairs`, `partial`, `partialRight`,
  * `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`,
  * `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `reverse`,
- * `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`, `splice`, `spread`,
- * `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`,
- * `thru`, `times`, `toArray`, `toPlainObject`, `transform`, `union`, `uniq`,
- * `unshift`, `unzip`, `values`, `valuesIn`, `where`, `without`, `wrap`, `xor`,
- * `zip`, and `zipObject`
+ * `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`, `sortByOrder`, `splice`,
+ * `spread`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`,
+ * `throttle`, `thru`, `times`, `toArray`, `toPlainObject`, `transform`,
+ * `union`, `uniq`, `unshift`, `unzip`, `values`, `valuesIn`, `where`,
+ * `without`, `wrap`, `xor`, `zip`, and `zipObject`
  *
  * The wrapper methods that are **not** chainable by default are:
- * `attempt`, `camelCase`, `capitalize`, `clone`, `cloneDeep`, `deburr`,
+ * `add`, `attempt`, `camelCase`, `capitalize`, `clone`, `cloneDeep`, `deburr`,
  * `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`,
  * `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`, `has`,
- * `identity`, `includes`, `indexOf`, `isArguments`, `isArray`, `isBoolean`,
- * `isDate`, `isElement`, `isEmpty`, `isEqual`, `isError`, `isFinite`,
- * `isFunction`, `isMatch`, `isNative`, `isNaN`, `isNull`, `isNumber`,
+ * `identity`, `includes`, `indexOf`, `inRange`, `isArguments`, `isArray`,
+ * `isBoolean`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isError`,
+ * `isFinite`,`isFunction`, `isMatch`, `isNative`, `isNaN`, `isNull`, `isNumber`,
  * `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`,
  * `isTypedArray`, `join`, `kebabCase`, `last`, `lastIndexOf`, `max`, `min`,
  * `noConflict`, `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`,
  * `random`, `reduce`, `reduceRight`, `repeat`, `result`, `runInContext`,
  * `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`,
- * `startCase`, `startsWith`, `template`, `trim`, `trimLeft`, `trimRight`,
- * `trunc`, `unescape`, `uniqueId`, `value`, and `words`
+ * `startCase`, `startsWith`, `sum`, `template`, `trim`, `trimLeft`,
+ * `trimRight`, `trunc`, `unescape`, `uniqueId`, `value`, and `words`
  *
  * The wrapper method `sample` will return a wrapped value when `n` is provided,
  * otherwise an unwrapped value is returned.
diff --git a/collection.js b/collection.js
index 351c74573..d1a94a5cb 100644
--- a/collection.js
+++ b/collection.js
@@ -23,8 +23,8 @@ import indexBy from './collection/indexBy';
 import inject from './collection/inject';
 import invoke from './collection/invoke';
 import map from './collection/map';
-import max from './collection/max';
-import min from './collection/min';
+import max from './math/max';
+import min from './math/min';
 import partition from './collection/partition';
 import pluck from './collection/pluck';
 import reduce from './collection/reduce';
@@ -37,6 +37,8 @@ import size from './collection/size';
 import some from './collection/some';
 import sortBy from './collection/sortBy';
 import sortByAll from './collection/sortByAll';
+import sortByOrder from './collection/sortByOrder';
+import sum from './math/sum';
 import where from './collection/where';
 
 export default {
@@ -79,5 +81,7 @@ export default {
   'some': some,
   'sortBy': sortBy,
   'sortByAll': sortByAll,
+  'sortByOrder': sortByOrder,
+  'sum': sum,
   'where': where
 };
diff --git a/collection/max.js b/collection/max.js
index 923d4bd42..29b9656bb 100644
--- a/collection/max.js
+++ b/collection/max.js
@@ -1,53 +1,2 @@
-import arrayMax from '../internal/arrayMax';
-import createExtremum from '../internal/createExtremum';
-
-/**
- * Gets the maximum value of `collection`. If `collection` is empty or falsey
- * `-Infinity` is returned. If an iteratee function is provided it is invoked
- * for each value in `collection` to generate the criterion by which the value
- * is ranked. The `iteratee` is bound to `thisArg` and invoked with three
- * arguments; (value, index, collection).
- *
- * If a property name is provided for `predicate` the created `_.property`
- * style callback returns the property value of the given element.
- *
- * If a value is also provided for `thisArg` the created `_.matchesProperty`
- * style callback returns `true` for elements that have a matching property
- * value, else `false`.
- *
- * If an object is provided for `predicate` the created `_.matches` style
- * callback returns `true` for elements that have the properties of the given
- * object, else `false`.
- *
- * @static
- * @memberOf _
- * @category Collection
- * @param {Array|Object|string} collection The collection to iterate over.
- * @param {Function|Object|string} [iteratee] The function invoked per iteration.
- * @param {*} [thisArg] The `this` binding of `iteratee`.
- * @returns {*} Returns the maximum value.
- * @example
- *
- * _.max([4, 2, 8, 6]);
- * // => 8
- *
- * _.max([]);
- * // => -Infinity
- *
- * var users = [
- *   { 'user': 'barney', 'age': 36 },
- *   { 'user': 'fred',   'age': 40 }
- * ];
- *
- * _.max(users, function(chr) {
- *   return chr.age;
- * });
- * // => { 'user': 'fred', 'age': 40 };
- *
- * // using the `_.property` callback shorthand
- * _.max(users, 'age');
- * // => { 'user': 'fred', 'age': 40 };
- */
-var max = createExtremum(arrayMax);
-
+import max from '../math/max'
 export default max;
diff --git a/collection/min.js b/collection/min.js
index a730ccb05..9c8a91efd 100644
--- a/collection/min.js
+++ b/collection/min.js
@@ -1,53 +1,2 @@
-import arrayMin from '../internal/arrayMin';
-import createExtremum from '../internal/createExtremum';
-
-/**
- * Gets the minimum value of `collection`. If `collection` is empty or falsey
- * `Infinity` is returned. If an iteratee function is provided it is invoked
- * for each value in `collection` to generate the criterion by which the value
- * is ranked. The `iteratee` is bound to `thisArg` and invoked with three
- * arguments; (value, index, collection).
- *
- * If a property name is provided for `predicate` the created `_.property`
- * style callback returns the property value of the given element.
- *
- * If a value is also provided for `thisArg` the created `_.matchesProperty`
- * style callback returns `true` for elements that have a matching property
- * value, else `false`.
- *
- * If an object is provided for `predicate` the created `_.matches` style
- * callback returns `true` for elements that have the properties of the given
- * object, else `false`.
- *
- * @static
- * @memberOf _
- * @category Collection
- * @param {Array|Object|string} collection The collection to iterate over.
- * @param {Function|Object|string} [iteratee] The function invoked per iteration.
- * @param {*} [thisArg] The `this` binding of `iteratee`.
- * @returns {*} Returns the minimum value.
- * @example
- *
- * _.min([4, 2, 8, 6]);
- * // => 2
- *
- * _.min([]);
- * // => Infinity
- *
- * var users = [
- *   { 'user': 'barney', 'age': 36 },
- *   { 'user': 'fred',   'age': 40 }
- * ];
- *
- * _.min(users, function(chr) {
- *   return chr.age;
- * });
- * // => { 'user': 'barney', 'age': 36 };
- *
- * // using the `_.property` callback shorthand
- * _.min(users, 'age');
- * // => { 'user': 'barney', 'age': 36 };
- */
-var min = createExtremum(arrayMin, true);
-
+import min from '../math/min'
 export default min;
diff --git a/collection/partition.js b/collection/partition.js
index ddd3b5124..5394bcab8 100644
--- a/collection/partition.js
+++ b/collection/partition.js
@@ -35,7 +35,7 @@ import createAggregator from '../internal/createAggregator';
  * _.partition([1.2, 2.3, 3.4], function(n) {
  *   return this.floor(n) % 2;
  * }, Math);
- * // => [[1, 3], [2]]
+ * // => [[1.2, 3.4], [2.3]]
  *
  * var users = [
  *   { 'user': 'barney',  'age': 36, 'active': false },
diff --git a/collection/size.js b/collection/size.js
index 0e47254bd..60816e9f9 100644
--- a/collection/size.js
+++ b/collection/size.js
@@ -2,8 +2,8 @@ import isLength from '../internal/isLength';
 import keys from '../object/keys';
 
 /**
- * Gets the size of `collection` by returning `collection.length` for
- * array-like values or the number of own enumerable properties for objects.
+ * Gets the size of `collection` by returning its length for array-like
+ * values or the number of own enumerable properties for objects.
  *
  * @static
  * @memberOf _
diff --git a/collection/sortBy.js b/collection/sortBy.js
index 6cc525a2f..28744a43e 100644
--- a/collection/sortBy.js
+++ b/collection/sortBy.js
@@ -55,8 +55,11 @@ import isLength from '../internal/isLength';
  * // => ['barney', 'fred', 'pebbles']
  */
 function sortBy(collection, iteratee, thisArg) {
+  if (collection == null) {
+    return [];
+  }
   var index = -1,
-      length = collection ? collection.length : 0,
+      length = collection.length,
       result = isLength(length) ? Array(length) : [];
 
   if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
diff --git a/collection/sortByAll.js b/collection/sortByAll.js
index 51d2be63f..075a165cb 100644
--- a/collection/sortByAll.js
+++ b/collection/sortByAll.js
@@ -1,9 +1,6 @@
-import baseEach from '../internal/baseEach';
 import baseFlatten from '../internal/baseFlatten';
-import baseSortBy from '../internal/baseSortBy';
-import compareMultipleAscending from '../internal/compareMultipleAscending';
+import baseSortByOrder from '../internal/baseSortByOrder';
 import isIterateeCall from '../internal/isIterateeCall';
-import isLength from '../internal/isLength';
 
 /**
  * This method is like `_.sortBy` except that it sorts by property names
@@ -29,25 +26,16 @@ import isLength from '../internal/isLength';
  * // => [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]]
  */
 function sortByAll(collection) {
-  var args = arguments;
-  if (args.length > 3 && isIterateeCall(args[1], args[2], args[3])) {
+  if (collection == null) {
+    return [];
+  }
+  var args = arguments,
+      guard = args[3];
+
+  if (guard && isIterateeCall(args[1], args[2], guard)) {
     args = [collection, args[1]];
   }
-  var index = -1,
-      length = collection ? collection.length : 0,
-      props = baseFlatten(args, false, false, 1),
-      result = isLength(length) ? Array(length) : [];
-
-  baseEach(collection, function(value) {
-    var length = props.length,
-        criteria = Array(length);
-
-    while (length--) {
-      criteria[length] = value == null ? undefined : value[props[length]];
-    }
-    result[++index] = { 'criteria': criteria, 'index': index, 'value': value };
-  });
-  return baseSortBy(result, compareMultipleAscending);
+  return baseSortByOrder(collection, baseFlatten(args, false, false, 1), []);
 }
 
 export default sortByAll;
diff --git a/collection/sortByOrder.js b/collection/sortByOrder.js
new file mode 100644
index 000000000..b226e1933
--- /dev/null
+++ b/collection/sortByOrder.js
@@ -0,0 +1,47 @@
+import baseSortByOrder from '../internal/baseSortByOrder';
+import isArray from '../lang/isArray';
+import isIterateeCall from '../internal/isIterateeCall';
+
+/**
+ * This method is like `_.sortByAll` except that it allows specifying the
+ * sort orders of the property names to sort by. A truthy value in `orders`
+ * will sort the corresponding property name in ascending order while a
+ * falsey value will sort it in descending order.
+ *
+ * @static
+ * @memberOf _
+ * @category Collection
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @param {string[]} props The property names to sort by.
+ * @param {boolean[]} orders The sort orders of `props`.
+ * @returns {Array} Returns the new sorted array.
+ * @example
+ *
+ * var users = [
+ *   { 'user': 'barney', 'age': 36 },
+ *   { 'user': 'fred',   'age': 40 },
+ *   { 'user': 'barney', 'age': 26 },
+ *   { 'user': 'fred',   'age': 30 }
+ * ];
+ *
+ * // sort by `user` in ascending order and by `age` in descending order
+ * _.map(_.sortByOrder(users, ['user', 'age'], [true, false]), _.values);
+ * // => [['barney', 36], ['barney', 26], ['fred', 40], ['fred', 30]]
+ */
+function sortByOrder(collection, props, orders, guard) {
+  if (collection == null) {
+    return [];
+  }
+  if (guard && isIterateeCall(props, orders, guard)) {
+    orders = null;
+  }
+  if (!isArray(props)) {
+    props = props == null ? [] : [props];
+  }
+  if (!isArray(orders)) {
+    orders = orders == null ? [] : [orders];
+  }
+  return baseSortByOrder(collection, props, orders);
+}
+
+export default sortByOrder;
diff --git a/collection/sum.js b/collection/sum.js
new file mode 100644
index 000000000..f4ad00270
--- /dev/null
+++ b/collection/sum.js
@@ -0,0 +1,2 @@
+import sum from '../math/sum'
+export default sum;
diff --git a/function/flow.js b/function/flow.js
index 072ab3635..a6da82918 100644
--- a/function/flow.js
+++ b/function/flow.js
@@ -1,8 +1,4 @@
-import arrayEvery from '../internal/arrayEvery';
-import baseIsFunction from '../internal/baseIsFunction';
-
-/** Used as the `TypeError` message for "Functions" methods. */
-var FUNC_ERROR_TEXT = 'Expected a function';
+import createComposer from '../internal/createComposer';
 
 /**
  * Creates a function that returns the result of invoking the provided
@@ -16,37 +12,14 @@ var FUNC_ERROR_TEXT = 'Expected a function';
  * @returns {Function} Returns the new function.
  * @example
  *
- * function add(x, y) {
- *   return x + y;
- * }
- *
  * function square(n) {
  *   return n * n;
  * }
  *
- * var addSquare = _.flow(add, square);
+ * var addSquare = _.flow(_.add, square);
  * addSquare(1, 2);
  * // => 9
  */
-function flow() {
-  var funcs = arguments,
-      length = funcs.length;
-
-  if (!length) {
-    return function() { return arguments[0]; };
-  }
-  if (!arrayEvery(funcs, baseIsFunction)) {
-    throw new TypeError(FUNC_ERROR_TEXT);
-  }
-  return function() {
-    var index = 0,
-        result = funcs[index].apply(this, arguments);
-
-    while (++index < length) {
-      result = funcs[index].call(this, result);
-    }
-    return result;
-  };
-}
+var flow = createComposer();
 
 export default flow;
diff --git a/function/flowRight.js b/function/flowRight.js
index 1425d2cbd..a1a8fc128 100644
--- a/function/flowRight.js
+++ b/function/flowRight.js
@@ -1,8 +1,4 @@
-import arrayEvery from '../internal/arrayEvery';
-import baseIsFunction from '../internal/baseIsFunction';
-
-/** Used as the `TypeError` message for "Functions" methods. */
-var FUNC_ERROR_TEXT = 'Expected a function';
+import createComposer from '../internal/createComposer';
 
 /**
  * This method is like `_.flow` except that it creates a function that
@@ -16,37 +12,14 @@ var FUNC_ERROR_TEXT = 'Expected a function';
  * @returns {Function} Returns the new function.
  * @example
  *
- * function add(x, y) {
- *   return x + y;
- * }
- *
  * function square(n) {
  *   return n * n;
  * }
  *
- * var addSquare = _.flowRight(square, add);
+ * var addSquare = _.flowRight(square, _.add);
  * addSquare(1, 2);
  * // => 9
  */
-function flowRight() {
-  var funcs = arguments,
-      fromIndex = funcs.length - 1;
-
-  if (fromIndex < 0) {
-    return function() { return arguments[0]; };
-  }
-  if (!arrayEvery(funcs, baseIsFunction)) {
-    throw new TypeError(FUNC_ERROR_TEXT);
-  }
-  return function() {
-    var index = fromIndex,
-        result = funcs[index].apply(this, arguments);
-
-    while (index--) {
-      result = funcs[index].call(this, result);
-    }
-    return result;
-  };
-}
+var flowRight = createComposer(true);
 
 export default flowRight;
diff --git a/function/memoize.js b/function/memoize.js
index 5d90cb8ad..5b0e89fe8 100644
--- a/function/memoize.js
+++ b/function/memoize.js
@@ -61,13 +61,14 @@ function memoize(func, resolver) {
     throw new TypeError(FUNC_ERROR_TEXT);
   }
   var memoized = function() {
-    var cache = memoized.cache,
-        key = resolver ? resolver.apply(this, arguments) : arguments[0];
+    var args = arguments,
+        cache = memoized.cache,
+        key = resolver ? resolver.apply(this, args) : args[0];
 
     if (cache.has(key)) {
       return cache.get(key);
     }
-    var result = func.apply(this, arguments);
+    var result = func.apply(this, args);
     cache.set(key, result);
     return result;
   };
diff --git a/internal/baseDifference.js b/internal/baseDifference.js
index 9aae88ea2..58028e7b9 100644
--- a/internal/baseDifference.js
+++ b/internal/baseDifference.js
@@ -42,7 +42,7 @@ function baseDifference(array, values) {
       }
       result.push(value);
     }
-    else if (indexOf(values, value) < 0) {
+    else if (indexOf(values, value, 0) < 0) {
       result.push(value);
     }
   }
diff --git a/internal/baseFlatten.js b/internal/baseFlatten.js
index 6dc272b71..ff0a993e1 100644
--- a/internal/baseFlatten.js
+++ b/internal/baseFlatten.js
@@ -9,13 +9,13 @@ import isObjectLike from './isObjectLike';
  *
  * @private
  * @param {Array} array The array to flatten.
- * @param {boolean} [isDeep] Specify a deep flatten.
- * @param {boolean} [isStrict] Restrict flattening to arrays and `arguments` objects.
- * @param {number} [fromIndex=0] The index to start from.
+ * @param {boolean} isDeep Specify a deep flatten.
+ * @param {boolean} isStrict Restrict flattening to arrays and `arguments` objects.
+ * @param {number} fromIndex The index to start from.
  * @returns {Array} Returns the new flattened array.
  */
 function baseFlatten(array, isDeep, isStrict, fromIndex) {
-  var index = (fromIndex || 0) - 1,
+  var index = fromIndex - 1,
       length = array.length,
       resIndex = -1,
       result = [];
@@ -26,7 +26,7 @@ function baseFlatten(array, isDeep, isStrict, fromIndex) {
     if (isObjectLike(value) && isLength(value.length) && (isArray(value) || isArguments(value))) {
       if (isDeep) {
         // Recursively flatten arrays (susceptible to call stack limits).
-        value = baseFlatten(value, isDeep, isStrict);
+        value = baseFlatten(value, isDeep, isStrict, 0);
       }
       var valIndex = -1,
           valLength = value.length;
diff --git a/internal/baseIndexOf.js b/internal/baseIndexOf.js
index d7fe970f5..3e14bfefb 100644
--- a/internal/baseIndexOf.js
+++ b/internal/baseIndexOf.js
@@ -6,14 +6,14 @@ import indexOfNaN from './indexOfNaN';
  * @private
  * @param {Array} array The array to search.
  * @param {*} value The value to search for.
- * @param {number} [fromIndex=0] The index to search from.
+ * @param {number} fromIndex The index to search from.
  * @returns {number} Returns the index of the matched value, else `-1`.
  */
 function baseIndexOf(array, value, fromIndex) {
   if (value !== value) {
     return indexOfNaN(array, fromIndex);
   }
-  var index = (fromIndex || 0) - 1,
+  var index = fromIndex - 1,
       length = array.length;
 
   while (++index < length) {
diff --git a/internal/baseSortBy.js b/internal/baseSortBy.js
index 26df3cdc9..aeb74542f 100644
--- a/internal/baseSortBy.js
+++ b/internal/baseSortBy.js
@@ -1,6 +1,6 @@
 /**
- * The base implementation of `_.sortBy` and `_.sortByAll` which uses `comparer`
- * to define the sort order of `array` and replaces criteria objects with their
+ * The base implementation of `_.sortBy` which uses `comparer` to define
+ * the sort order of `array` and replaces criteria objects with their
  * corresponding values.
  *
  * @private
diff --git a/internal/baseSortByOrder.js b/internal/baseSortByOrder.js
new file mode 100644
index 000000000..41703ee96
--- /dev/null
+++ b/internal/baseSortByOrder.js
@@ -0,0 +1,35 @@
+import baseEach from './baseEach';
+import baseSortBy from './baseSortBy';
+import compareMultiple from './compareMultiple';
+import isLength from './isLength';
+
+/**
+ * The base implementation of `_.sortByOrder` without param guards.
+ *
+ * @private
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @param {string[]} props The property names to sort by.
+ * @param {boolean[]} orders The sort orders of `props`.
+ * @returns {Array} Returns the new sorted array.
+ */
+function baseSortByOrder(collection, props, orders) {
+  var index = -1,
+      length = collection.length,
+      result = isLength(length) ? Array(length) : [];
+
+  baseEach(collection, function(value) {
+    var length = props.length,
+        criteria = Array(length);
+
+    while (length--) {
+      criteria[length] = value == null ? undefined : value[props[length]];
+    }
+    result[++index] = { 'criteria': criteria, 'index': index, 'value': value };
+  });
+
+  return baseSortBy(result, function(object, other) {
+    return compareMultiple(object, other, orders);
+  });
+}
+
+export default baseSortByOrder;
diff --git a/internal/baseUniq.js b/internal/baseUniq.js
index c5894a2d2..836ee68f0 100644
--- a/internal/baseUniq.js
+++ b/internal/baseUniq.js
@@ -44,7 +44,7 @@ function baseUniq(array, iteratee) {
       }
       result.push(value);
     }
-    else if (indexOf(seen, computed) < 0) {
+    else if (indexOf(seen, computed, 0) < 0) {
       if (iteratee || isLarge) {
         seen.push(computed);
       }
diff --git a/internal/compareMultipleAscending.js b/internal/compareMultiple.js
similarity index 57%
rename from internal/compareMultipleAscending.js
rename to internal/compareMultiple.js
index eb24af85c..91020a8ae 100644
--- a/internal/compareMultipleAscending.js
+++ b/internal/compareMultiple.js
@@ -1,24 +1,34 @@
 import baseCompareAscending from './baseCompareAscending';
 
 /**
- * Used by `_.sortByAll` to compare multiple properties of each element
- * in a collection and stable sort them in ascending order.
+ * Used by `_.sortByOrder` to compare multiple properties of each element
+ * in a collection and stable sort them in the following order:
+ *
+ * If orders is unspecified, sort in ascending order for all properties.
+ * Otherwise, for each property, sort in ascending order if its corresponding value in
+ * orders is true, and descending order if false.
  *
  * @private
  * @param {Object} object The object to compare to `other`.
  * @param {Object} other The object to compare to `object`.
+ * @param {boolean[]} orders The order to sort by for each property.
  * @returns {number} Returns the sort order indicator for `object`.
  */
-function compareMultipleAscending(object, other) {
+function compareMultiple(object, other, orders) {
   var index = -1,
       objCriteria = object.criteria,
       othCriteria = other.criteria,
-      length = objCriteria.length;
+      length = objCriteria.length,
+      ordersLength = orders.length;
 
   while (++index < length) {
     var result = baseCompareAscending(objCriteria[index], othCriteria[index]);
     if (result) {
-      return result;
+      if (index >= ordersLength) {
+        return result;
+      } else {
+        return orders[index] ? result : result * -1;
+      }
     }
   }
   // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
@@ -31,4 +41,4 @@ function compareMultipleAscending(object, other) {
   return object.index - other.index;
 }
 
-export default compareMultipleAscending;
+export default compareMultiple;
diff --git a/internal/createAssigner.js b/internal/createAssigner.js
index 46d3a03e1..480907b1b 100644
--- a/internal/createAssigner.js
+++ b/internal/createAssigner.js
@@ -11,24 +11,31 @@ import isIterateeCall from './isIterateeCall';
  */
 function createAssigner(assigner) {
   return function() {
-    var length = arguments.length,
-        object = arguments[0];
+    var args = arguments,
+        length = args.length,
+        object = args[0];
 
     if (length < 2 || object == null) {
       return object;
     }
-    if (length > 3 && isIterateeCall(arguments[1], arguments[2], arguments[3])) {
-      length = 2;
+    var customizer = args[length - 2],
+        thisArg = args[length - 1],
+        guard = args[3];
+
+    if (length > 3 && typeof customizer == 'function') {
+      customizer = bindCallback(customizer, thisArg, 5);
+      length -= 2;
+    } else {
+      customizer = (length > 2 && typeof thisArg == 'function') ? thisArg : null;
+      length -= (customizer ? 1 : 0);
     }
-    // Juggle arguments.
-    if (length > 3 && typeof arguments[length - 2] == 'function') {
-      var customizer = bindCallback(arguments[--length - 1], arguments[length--], 5);
-    } else if (length > 2 && typeof arguments[length - 1] == 'function') {
-      customizer = arguments[--length];
+    if (guard && isIterateeCall(args[1], args[2], guard)) {
+      customizer = length == 3 ? null : customizer;
+      length = 2;
     }
     var index = 0;
     while (++index < length) {
-      var source = arguments[index];
+      var source = args[index];
       if (source) {
         assigner(object, source, customizer);
       }
diff --git a/internal/createComposer.js b/internal/createComposer.js
new file mode 100644
index 000000000..f0be26990
--- /dev/null
+++ b/internal/createComposer.js
@@ -0,0 +1,39 @@
+/** Used as the `TypeError` message for "Functions" methods. */
+var FUNC_ERROR_TEXT = 'Expected a function';
+
+/**
+ * Creates a function to compose other functions into a single function.
+ *
+ * @private
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {Function} Returns the new composer function.
+ */
+function createComposer(fromRight) {
+  return function() {
+    var length = arguments.length,
+        index = length,
+        fromIndex = fromRight ? length - 1 : 0;
+
+    if (!length) {
+      return function() { return arguments[0]; };
+    }
+    var funcs = Array(length);
+    while (index--) {
+      funcs[index] = arguments[index];
+      if (typeof funcs[index] != 'function') {
+        throw new TypeError(FUNC_ERROR_TEXT);
+      }
+    }
+    return function() {
+      var index = fromIndex,
+          result = funcs[index].apply(this, arguments);
+
+      while ((fromRight ? index-- : ++index < length)) {
+        result = funcs[index].call(this, result);
+      }
+      return result;
+    };
+  };
+}
+
+export default createComposer;
diff --git a/internal/indexOfNaN.js b/internal/indexOfNaN.js
index f6472d996..18c2af405 100644
--- a/internal/indexOfNaN.js
+++ b/internal/indexOfNaN.js
@@ -4,13 +4,13 @@
  *
  * @private
  * @param {Array} array The array to search.
- * @param {number} [fromIndex] The index to search from.
+ * @param {number} fromIndex The index to search from.
  * @param {boolean} [fromRight] Specify iterating from right to left.
  * @returns {number} Returns the index of the matched `NaN`, else `-1`.
  */
 function indexOfNaN(array, fromIndex, fromRight) {
   var length = array.length,
-      index = fromRight ? (fromIndex || length) : ((fromIndex || 0) - 1);
+      index = fromIndex + (fromRight ? 0 : -1);
 
   while ((fromRight ? index-- : ++index < length)) {
     var other = array[index];
diff --git a/internal/lazyValue.js b/internal/lazyValue.js
index 2f1a01b96..f128f85f6 100644
--- a/internal/lazyValue.js
+++ b/internal/lazyValue.js
@@ -3,8 +3,9 @@ import getView from './getView';
 import isArray from '../lang/isArray';
 
 /** Used to indicate the type of lazy iteratees. */
-var LAZY_FILTER_FLAG = 0,
-    LAZY_MAP_FLAG = 1;
+var LAZY_DROP_WHILE_FLAG = 0,
+    LAZY_MAP_FLAG = 2,
+    LAZY_TAKE_WHILE_FLAG = 3;
 
 /* Native method references for those with the same name as other `lodash` methods. */
 var nativeMin = Math.min;
@@ -46,16 +47,22 @@ function lazyValue() {
     while (++iterIndex < iterLength) {
       var data = iteratees[iterIndex],
           iteratee = data.iteratee,
-          computed = iteratee(value, index, array),
           type = data.type;
 
+      if (type != LAZY_DROP_WHILE_FLAG) {
+        var computed = iteratee(value);
+      } else {
+        data.done = data.done && (isRight ? index < data.index : index > data.index);
+        data.index = index;
+        computed = data.done || (data.done = !iteratee(value));
+      }
       if (type == LAZY_MAP_FLAG) {
         value = computed;
       } else if (!computed) {
-        if (type == LAZY_FILTER_FLAG) {
-          continue outer;
-        } else {
+        if (type == LAZY_TAKE_WHILE_FLAG) {
           break outer;
+        } else {
+          continue outer;
         }
       }
     }
diff --git a/internal/root.js b/internal/root.js
index c326966a8..2809c72e3 100644
--- a/internal/root.js
+++ b/internal/root.js
@@ -4,24 +4,24 @@ var objectTypes = {
   'object': true
 };
 
-/**
- * Used as a reference to the global object.
- *
- * The `this` value is used if it is the global object to avoid Greasemonkey's
- * restricted `window` object, otherwise the `window` object is used.
- */
-var root = (objectTypes[typeof window] && window !== (this && this.window)) ? window : this;
-
 /** Detect free variable `exports`. */
 var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports;
 
 /** Detect free variable `module`. */
 var freeModule = objectTypes[typeof module] && module && !module.nodeType && module;
 
-/** Detect free variable `global` from Node.js or Browserified code and use it as `root`. */
+/** Detect free variable `global` from Node.js. */
 var freeGlobal = freeExports && freeModule && typeof global == 'object' && global;
-if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal || freeGlobal.self === freeGlobal)) {
-  root = freeGlobal;
-}
+
+/** Detect free variable `window`. */
+var freeWindow = objectTypes[typeof window] && window;
+
+/**
+ * Used as a reference to the global object.
+ *
+ * The `this` value is used if it is the global object to avoid Greasemonkey's
+ * restricted `window` object, otherwise the `window` object is used.
+ */
+var root = freeGlobal || ((freeWindow !== (this && this.window)) && freeWindow) || this;
 
 export default root;
diff --git a/lang/isEmpty.js b/lang/isEmpty.js
index 8a6adffa4..11e5fb898 100644
--- a/lang/isEmpty.js
+++ b/lang/isEmpty.js
@@ -7,7 +7,7 @@ import isString from './isString';
 import keys from '../object/keys';
 
 /**
- * Checks if a value is empty. A value is considered empty unless it is an
+ * Checks if `value` is empty. A value is considered empty unless it is an
  * `arguments` object, array, string, or jQuery-like collection with a length
  * greater than `0` or an object with own enumerable properties.
  *
diff --git a/lodash.js b/lodash.js
index b6e93355c..a49d964f7 100644
--- a/lodash.js
+++ b/lodash.js
@@ -1,6 +1,6 @@
 /**
  * @license
- * lodash 3.3.1 (Custom Build) <https://lodash.com/>
+ * lodash 3.4.0 (Custom Build) <https://lodash.com/>
  * Build: `lodash modularize modern exports="es" -o ./`
  * Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
  * Based on Underscore.js 1.8.2 <http://underscorejs.org/LICENSE>
@@ -13,6 +13,7 @@ import collection from './collection';
 import date from './date';
 import func from './function';
 import lang from './lang';
+import math from './math';
 import number from './number';
 import object from './object';
 import string from './string';
@@ -38,11 +39,11 @@ import support from './support';
 import thru from './chain/thru';
 
 /** Used as the semantic version number. */
-var VERSION = '3.3.1';
+var VERSION = '3.4.0';
 
 /** Used to indicate the type of lazy iteratees. */
-var LAZY_FILTER_FLAG = 0,
-    LAZY_WHILE_FLAG = 2;
+var LAZY_DROP_WHILE_FLAG = 0,
+    LAZY_MAP_FLAG = 2;
 
 /** Used for native method references. */
 var arrayProto = Array.prototype;
@@ -150,6 +151,7 @@ lodash.shuffle = collection.shuffle;
 lodash.slice = array.slice;
 lodash.sortBy = collection.sortBy;
 lodash.sortByAll = collection.sortByAll;
+lodash.sortByOrder = collection.sortByOrder;
 lodash.spread = func.spread;
 lodash.take = array.take;
 lodash.takeRight = array.takeRight;
@@ -192,6 +194,7 @@ lodash.unique = array.uniq;
 mixin(lodash, lodash);
 
 // Add functions that return unwrapped values when chaining.
+lodash.add = math.add;
 lodash.attempt = utility.attempt;
 lodash.camelCase = string.camelCase;
 lodash.capitalize = string.capitalize;
@@ -239,8 +242,8 @@ lodash.isUndefined = lang.isUndefined;
 lodash.kebabCase = string.kebabCase;
 lodash.last = array.last;
 lodash.lastIndexOf = array.lastIndexOf;
-lodash.max = collection.max;
-lodash.min = collection.min;
+lodash.max = math.max;
+lodash.min = math.min;
 lodash.noop = utility.noop;
 lodash.now = date.now;
 lodash.pad = string.pad;
@@ -259,6 +262,7 @@ lodash.sortedIndex = array.sortedIndex;
 lodash.sortedLastIndex = array.sortedLastIndex;
 lodash.startCase = string.startCase;
 lodash.startsWith = string.startsWith;
+lodash.sum = math.sum;
 lodash.template = string.template;
 lodash.trim = string.trim;
 lodash.trimLeft = string.trimLeft;
@@ -319,15 +323,17 @@ arrayEach(['bind', 'bindKey', 'curry', 'curryRight', 'partial', 'partialRight'],
 });
 
 // Add `LazyWrapper` methods that accept an `iteratee` value.
-arrayEach(['filter', 'map', 'takeWhile'], function(methodName, index) {
-  var isFilter = index == LAZY_FILTER_FLAG || index == LAZY_WHILE_FLAG;
+arrayEach(['dropWhile', 'filter', 'map', 'takeWhile'], function(methodName, type) {
+  var isFilter = type != LAZY_MAP_FLAG,
+      isDropWhile = type == LAZY_DROP_WHILE_FLAG;
 
   LazyWrapper.prototype[methodName] = function(iteratee, thisArg) {
-    var result = this.clone(),
+    var filtered = this.__filtered__,
+        result = (filtered && isDropWhile) ? new LazyWrapper(this) : this.clone(),
         iteratees = result.__iteratees__ || (result.__iteratees__ = []);
 
-    result.__filtered__ = result.__filtered__ || isFilter;
-    iteratees.push({ 'iteratee': baseCallback(iteratee, thisArg, 3), 'type': index });
+    result.__filtered__ = filtered || isFilter;
+    iteratees.push({ 'done': false, 'index': 0, 'iteratee': baseCallback(iteratee, thisArg, 1), 'type': type });
     return result;
   };
 });
@@ -392,23 +398,10 @@ LazyWrapper.prototype.compact = function() {
   return this.filter(identity);
 };
 
-LazyWrapper.prototype.dropWhile = function(predicate, thisArg) {
-  var done,
-      lastIndex,
-      isRight = this.__dir__ < 0;
-
-  predicate = baseCallback(predicate, thisArg, 3);
-  return this.filter(function(value, index, array) {
-    done = done && (isRight ? index < lastIndex : index > lastIndex);
-    lastIndex = index;
-    return done || (done = !predicate(value, index, array));
-  });
-};
-
 LazyWrapper.prototype.reject = function(predicate, thisArg) {
-  predicate = baseCallback(predicate, thisArg, 3);
-  return this.filter(function(value, index, array) {
-    return !predicate(value, index, array);
+  predicate = baseCallback(predicate, thisArg, 1);
+  return this.filter(function(value) {
+    return !predicate(value);
   });
 };
 
@@ -430,16 +423,24 @@ LazyWrapper.prototype.toArray = function() {
 // Add `LazyWrapper` methods to `lodash.prototype`.
 baseForOwn(LazyWrapper.prototype, function(func, methodName) {
   var lodashFunc = lodash[methodName],
+      checkIteratee = /^(?:filter|map|reject)|While$/.test(methodName),
       retUnwrapped = /^(?:first|last)$/.test(methodName);
 
   lodash.prototype[methodName] = function() {
-    var value = this.__wrapped__,
-        args = arguments,
+    var args = arguments,
+        length = args.length,
         chainAll = this.__chain__,
+        value = this.__wrapped__,
         isHybrid = !!this.__actions__.length,
         isLazy = value instanceof LazyWrapper,
-        onlyLazy = isLazy && !isHybrid;
+        iteratee = args[0],
+        useLazy = isLazy || isArray(value);
 
+    if (useLazy && checkIteratee && typeof iteratee == 'function' && iteratee.length != 1) {
+      // avoid lazy use if the iteratee has a `length` other than `1`
+      isLazy = useLazy = false;
+    }
+    var onlyLazy = isLazy && !isHybrid;
     if (retUnwrapped && !chainAll) {
       return onlyLazy
         ? func.call(value)
@@ -450,7 +451,7 @@ baseForOwn(LazyWrapper.prototype, function(func, methodName) {
       push.apply(otherArgs, args);
       return lodashFunc.apply(lodash, otherArgs);
     };
-    if (isLazy || isArray(value)) {
+    if (useLazy) {
       var wrapper = onlyLazy ? value : new LazyWrapper(this),
           result = func.apply(wrapper, args);
 
diff --git a/math.js b/math.js
new file mode 100644
index 000000000..b91229c03
--- /dev/null
+++ b/math.js
@@ -0,0 +1,11 @@
+import add from './math/add';
+import max from './math/max';
+import min from './math/min';
+import sum from './math/sum';
+
+export default {
+  'add': add,
+  'max': max,
+  'min': min,
+  'sum': sum
+};
diff --git a/math/add.js b/math/add.js
new file mode 100644
index 000000000..39b53553c
--- /dev/null
+++ b/math/add.js
@@ -0,0 +1,19 @@
+/**
+ * Adds two numbers.
+ *
+ * @static
+ * @memberOf _
+ * @category Math
+ * @param {number} augend The first number to add.
+ * @param {number} addend The second number to add.
+ * @returns {number} Returns the sum.
+ * @example
+ *
+ * _.add(6, 4);
+ * // => 10
+ */
+function add(augend, addend) {
+  return augend + addend;
+}
+
+export default add;
diff --git a/math/max.js b/math/max.js
new file mode 100644
index 000000000..10dd13464
--- /dev/null
+++ b/math/max.js
@@ -0,0 +1,53 @@
+import arrayMax from '../internal/arrayMax';
+import createExtremum from '../internal/createExtremum';
+
+/**
+ * Gets the maximum value of `collection`. If `collection` is empty or falsey
+ * `-Infinity` is returned. If an iteratee function is provided it is invoked
+ * for each value in `collection` to generate the criterion by which the value
+ * is ranked. The `iteratee` is bound to `thisArg` and invoked with three
+ * arguments; (value, index, collection).
+ *
+ * If a property name is provided for `predicate` the created `_.property`
+ * style callback returns the property value of the given element.
+ *
+ * If a value is also provided for `thisArg` the created `_.matchesProperty`
+ * style callback returns `true` for elements that have a matching property
+ * value, else `false`.
+ *
+ * If an object is provided for `predicate` the created `_.matches` style
+ * callback returns `true` for elements that have the properties of the given
+ * object, else `false`.
+ *
+ * @static
+ * @memberOf _
+ * @category Math
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @param {Function|Object|string} [iteratee] The function invoked per iteration.
+ * @param {*} [thisArg] The `this` binding of `iteratee`.
+ * @returns {*} Returns the maximum value.
+ * @example
+ *
+ * _.max([4, 2, 8, 6]);
+ * // => 8
+ *
+ * _.max([]);
+ * // => -Infinity
+ *
+ * var users = [
+ *   { 'user': 'barney', 'age': 36 },
+ *   { 'user': 'fred',   'age': 40 }
+ * ];
+ *
+ * _.max(users, function(chr) {
+ *   return chr.age;
+ * });
+ * // => { 'user': 'fred', 'age': 40 };
+ *
+ * // using the `_.property` callback shorthand
+ * _.max(users, 'age');
+ * // => { 'user': 'fred', 'age': 40 };
+ */
+var max = createExtremum(arrayMax);
+
+export default max;
diff --git a/math/min.js b/math/min.js
new file mode 100644
index 000000000..dd3a2d5a3
--- /dev/null
+++ b/math/min.js
@@ -0,0 +1,53 @@
+import arrayMin from '../internal/arrayMin';
+import createExtremum from '../internal/createExtremum';
+
+/**
+ * Gets the minimum value of `collection`. If `collection` is empty or falsey
+ * `Infinity` is returned. If an iteratee function is provided it is invoked
+ * for each value in `collection` to generate the criterion by which the value
+ * is ranked. The `iteratee` is bound to `thisArg` and invoked with three
+ * arguments; (value, index, collection).
+ *
+ * If a property name is provided for `predicate` the created `_.property`
+ * style callback returns the property value of the given element.
+ *
+ * If a value is also provided for `thisArg` the created `_.matchesProperty`
+ * style callback returns `true` for elements that have a matching property
+ * value, else `false`.
+ *
+ * If an object is provided for `predicate` the created `_.matches` style
+ * callback returns `true` for elements that have the properties of the given
+ * object, else `false`.
+ *
+ * @static
+ * @memberOf _
+ * @category Math
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @param {Function|Object|string} [iteratee] The function invoked per iteration.
+ * @param {*} [thisArg] The `this` binding of `iteratee`.
+ * @returns {*} Returns the minimum value.
+ * @example
+ *
+ * _.min([4, 2, 8, 6]);
+ * // => 2
+ *
+ * _.min([]);
+ * // => Infinity
+ *
+ * var users = [
+ *   { 'user': 'barney', 'age': 36 },
+ *   { 'user': 'fred',   'age': 40 }
+ * ];
+ *
+ * _.min(users, function(chr) {
+ *   return chr.age;
+ * });
+ * // => { 'user': 'barney', 'age': 36 };
+ *
+ * // using the `_.property` callback shorthand
+ * _.min(users, 'age');
+ * // => { 'user': 'barney', 'age': 36 };
+ */
+var min = createExtremum(arrayMin, true);
+
+export default min;
diff --git a/math/sum.js b/math/sum.js
new file mode 100644
index 000000000..b0ef03ece
--- /dev/null
+++ b/math/sum.js
@@ -0,0 +1,33 @@
+import isArray from '../lang/isArray';
+import toIterable from '../internal/toIterable';
+
+/**
+ * Gets the sum of the values in `collection`.
+ *
+ * @static
+ * @memberOf _
+ * @category Math
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @returns {number} Returns the sum.
+ * @example
+ *
+ * _.sum([4, 6, 2]);
+ * // => 12
+ *
+ * _.sum({ 'a': 4, 'b': 6, 'c': 2 });
+ * // => 12
+ */
+function sum(collection) {
+  if (!isArray(collection)) {
+    collection = toIterable(collection);
+  }
+  var length = collection.length,
+      result = 0;
+
+  while (length--) {
+    result += +collection[length] || 0;
+  }
+  return result;
+}
+
+export default sum;
diff --git a/number/inRange.js b/number/inRange.js
index 75c9e41d4..a4f328f0d 100644
--- a/number/inRange.js
+++ b/number/inRange.js
@@ -1,6 +1,6 @@
 /**
  * Checks if `n` is between `start` and up to but not including, `end`. If
- * `end` is not specified it defaults to `start` with `start` becoming `0`.
+ * `end` is not specified it is set to `start` with `start` then set to `0`.
  *
  * @static
  * @memberOf _
diff --git a/object/defaults.js b/object/defaults.js
index 5c5fe4815..759c6d89b 100644
--- a/object/defaults.js
+++ b/object/defaults.js
@@ -5,7 +5,7 @@ import assignDefaults from '../internal/assignDefaults';
 /**
  * Assigns own enumerable properties of source object(s) to the destination
  * object for all destination properties that resolve to `undefined`. Once a
- * property is set, additional defaults of the same property are ignored.
+ * property is set, additional values of the same property are ignored.
  *
  * @static
  * @memberOf _
diff --git a/package.json b/package.json
index 376625a00..364370f75 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "lodash-es",
-  "version": "3.3.1",
+  "version": "3.4.0",
   "description": "The modern build of lodash exported as ES modules.",
   "homepage": "https://lodash.com/custom-builds",
   "license": "MIT",
diff --git a/string/escape.js b/string/escape.js
index f497cd836..341b07429 100644
--- a/string/escape.js
+++ b/string/escape.js
@@ -6,7 +6,7 @@ var reUnescapedHtml = /[&<>"'`]/g,
     reHasUnescapedHtml = RegExp(reUnescapedHtml.source);
 
 /**
- * Converts the characters "&", "<", ">", '"', "'", and '`', in `string` to
+ * Converts the characters "&", "<", ">", '"', "'", and "\`", in `string` to
  * their corresponding HTML entities.
  *
  * **Note:** No other characters are escaped. To escape additional characters
diff --git a/string/words.js b/string/words.js
index 2d3389f88..be3fba9ce 100644
--- a/string/words.js
+++ b/string/words.js
@@ -6,7 +6,7 @@ var reWords = (function() {
   var upper = '[A-Z\\xc0-\\xd6\\xd8-\\xde]',
       lower = '[a-z\\xdf-\\xf6\\xf8-\\xff]+';
 
-  return RegExp(upper + '{2,}(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g');
+  return RegExp(upper + '+(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g');
 }());
 
 /**
diff --git a/utility/attempt.js b/utility/attempt.js
index baa49683a..b6e26caa9 100644
--- a/utility/attempt.js
+++ b/utility/attempt.js
@@ -21,14 +21,14 @@ import isError from '../lang/isError';
  * }
  */
 function attempt() {
-  var length = arguments.length,
-      func = arguments[0];
+  var func = arguments[0],
+      length = arguments.length,
+      args = Array(length ? length - 1 : 0);
 
+  while (--length > 0) {
+    args[length - 1] = arguments[length];
+  }
   try {
-    var args = Array(length ? length - 1 : 0);
-    while (--length > 0) {
-      args[length - 1] = arguments[length];
-    }
     return func.apply(undefined, args);
   } catch(e) {
     return isError(e) ? e : new Error(e);
diff --git a/utility/range.js b/utility/range.js
index 85c1d7675..dedcdbc04 100644
--- a/utility/range.js
+++ b/utility/range.js
@@ -8,9 +8,9 @@ var nativeMax = Math.max;
 
 /**
  * Creates an array of numbers (positive and/or negative) progressing from
- * `start` up to, but not including, `end`. If `end` is not specified it
- * defaults to `start` with `start` becoming `0`. If `start` is less than
- * `end` a zero-length range is created unless a negative `step` is specified.
+ * `start` up to, but not including, `end`. If `end` is not specified it is
+ * set to `start` with `start` then set to `0`. If `start` is less than `end`
+ * a zero-length range is created unless a negative `step` is specified.
  *
  * @static
  * @memberOf _