diff --git a/Data/Semigroup.hs b/Data/Semigroup.hs
--- a/Data/Semigroup.hs
+++ b/Data/Semigroup.hs
@@ -8,6 +8,13 @@
 -- Stability   :  provisional
 -- Portability :  portable
 --
+-- In mathematics, a semigroup is an algebraic structure consisting of a 
+-- set together with an associative binary operation. A semigroup 
+-- generalizes a monoid in that there might not exist an identity 
+-- element. It also (originally) generalized a group (a monoid with all 
+-- inverses) to a type where every element did not have to have an inverse, 
+-- thus the name semigroup.
+--
 ----------------------------------------------------------------------------
 module Data.Semigroup ( 
     Semigroup(..)
@@ -56,14 +63,21 @@
 infixl 6 <> 
 
 class Semigroup a where
+  -- | An associative operation. 
+  -- 
+  -- > (a <> b) <> c = a <> (b <> c)
   (<>) :: a -> a -> a
 
+  -- | Reduce a non-empty list with (<>)
   sconcat :: NonEmpty a -> a
   sconcat (a :| as) = go a as where
     go b (c:cs) = b <> go c cs
     go b []     = b
 
-  -- replicate1p n r = replicate (1 + n) r
+  -- | /O(log n)/ Repeat a value (n + 1) times.
+  --
+  -- > replicate1p n a = a <> a <> ... n + 1 times <> a
+  
   replicate1p :: Whole n => n -> a -> a
   replicate1p y0 x0 = f x0 (1 Prelude.+ y0)
     where
@@ -210,6 +224,8 @@
 
 -- (==)/XNOR on Bool forms a 'Semigroup', but has no good name
 
+
+-- | Provide a Semigroup for an arbitrary Monoid.
 newtype WrappedMonoid m = WrapMonoid 
   { unwrapMonoid :: m } deriving 
   ( Eq, Ord, Bounded, Show, Read
diff --git a/Numeric/Natural.hs b/Numeric/Natural.hs
--- a/Numeric/Natural.hs
+++ b/Numeric/Natural.hs
@@ -1,3 +1,16 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Numeric.Natural
+-- Copyright   :  (C) 2011 Edward Kmett,
+-- License     :  BSD-style (see the file LICENSE)
+--
+-- Maintainer  :  Edward Kmett <ekmett@gmail.com>
+-- Stability   :  provisional
+-- Portability :  portable
+--
+-- Natural numbers.
+--
+----------------------------------------------------------------------------
 module Numeric.Natural 
   ( Natural
   , Whole(toNatural)
diff --git a/Numeric/Natural/Internal.hs b/Numeric/Natural/Internal.hs
--- a/Numeric/Natural/Internal.hs
+++ b/Numeric/Natural/Internal.hs
@@ -1,3 +1,17 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Numeric.Natural.Internal
+-- Copyright   :  (C) 2011 Edward Kmett,
+-- License     :  BSD-style (see the file LICENSE)
+--
+-- Maintainer  :  Edward Kmett <ekmett@gmail.com>
+-- Stability   :  provisional
+-- Portability :  portable
+--
+-- This module exposes the potentially unsafe operations that are sometimes
+-- needed for efficiency: The Natural data constructor and unsafePred.
+--
+----------------------------------------------------------------------------
 module Numeric.Natural.Internal
   ( Natural(..)
   , Whole(..)
@@ -67,6 +81,7 @@
   quotRem (Natural a) (Natural b) = (Natural q, Natural r) where (q,r) = quotRem a b
   toInteger = runNatural
 
+-- | A refinement of Integral to represent types that do not contain negative numbers.
 class Integral n => Whole n where
   toNatural :: n -> Natural
   unsafePred :: n -> n
diff --git a/semigroups.cabal b/semigroups.cabal
--- a/semigroups.cabal
+++ b/semigroups.cabal
@@ -1,6 +1,6 @@
 name:          semigroups
 category:      Algebra, Data, Data Structures, Math
-version:       0.7.1
+version:       0.7.1.1
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
@@ -10,7 +10,10 @@
 homepage:      http://github.com/ekmett/semigroups/
 copyright:     Copyright (C) 2011 Edward A. Kmett
 synopsis:      Haskell 98 semigroups
-description:   Haskell 98 semigroups
+description:   
+    Haskell 98 semigroups
+    .
+    In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative binary operation. A semigroup generalizes a monoid in that there might not exist an identity element. It also (originally) generalized a group (a monoid with all inverses) to a type where every element did not have to have an inverse, thus the name semigroup.
 build-type:    Simple  
 
 source-repository head