Time for an 2014 update…

Task/Sorting-algorithms-Quicksort/Ruby/sorting-algorithms-quicksort-1.rb

@@ -1,7 +1,7 @@
 class Array
   def quick_sort
     return self if length <= 1
-    pivot = self[length / 2]
+    pivot = sample
     find_all { |i| i <  pivot }.quick_sort +
       find_all { |i| i == pivot } +
       find_all { |i| i >  pivot }.quick_sort

Task/Sorting-algorithms-Quicksort/Ruby/sorting-algorithms-quicksort-2.rb

@@ -3,8 +3,6 @@ class Array
     return self if length <= 1
     pivot = self[0]
     less, greatereq = self[1..-1].partition { |x| x < pivot }
-    less.quick_sort +
-      [pivot] +
-      greatereq.quick_sort
+    less.quick_sort + [pivot] + greatereq.quick_sort
   end
 end

Task/Sorting-algorithms-Quicksort/Ruby/sorting-algorithms-quicksort-3.rb

@@ -0,0 +1,9 @@
+class Array
+  def quick_sort
+    return self if length <= 1
+    pivot = sample
+    group = group_by{ |x| x <=> pivot }
+    group.default = []
+    group[-1].quick_sort + group[0] + group[1].quick_sort
+  end
+end