A few more length variables.

underscore.js

@@ -78,7 +78,7 @@
     if (nativeForEach && obj.forEach === nativeForEach) {
       obj.forEach(iterator, context);
     } else if (obj.length === +obj.length) {
-      for (var i = 0, l = obj.length; i < l; i++) {
+      for (var i = 0, length = obj.length; i < length; i++) {
         if (iterator.call(context, obj[i], i, obj) === breaker) return;
       }
     } else {
@@ -508,7 +508,7 @@
   _.object = function(list, values) {
     if (list == null) return {};
     var result = {};
-    for (var i = 0, l = list.length; i < l; i++) {
+    for (var i = 0, length = list.length; i < length; i++) {
       if (values) {
         result[list[i]] = values[i];
       } else {
@@ -526,17 +526,17 @@
   // for **isSorted** to use binary search.
   _.indexOf = function(array, item, isSorted) {
     if (array == null) return -1;
-    var i = 0, l = array.length;
+    var i = 0, length = array.length;
     if (isSorted) {
       if (typeof isSorted == 'number') {
-        i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted);
+        i = (isSorted < 0 ? Math.max(0, length + isSorted) : isSorted);
       } else {
         i = _.sortedIndex(array, item);
         return array[i] === item ? i : -1;
       }
     }
     if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted);
-    for (; i < l; i++) if (array[i] === item) return i;
+    for (; i < length; i++) if (array[i] === item) return i;
     return -1;
   };
 
@@ -562,11 +562,11 @@
     }
     step = arguments[2] || 1;
 
-    var len = Math.max(Math.ceil((stop - start) / step), 0);
+    var length = Math.max(Math.ceil((stop - start) / step), 0);
     var idx = 0;
-    var range = new Array(len);
+    var range = new Array(length);
 
-    while(idx < len) {
+    while(idx < length) {
       range[idx++] = start;
       start += step;
     }