diff --git a/Algebra/Classes.hs b/Algebra/Classes.hs
--- a/Algebra/Classes.hs
+++ b/Algebra/Classes.hs
@@ -2,7 +2,7 @@
 module Algebra.Classes where
 
 import Prelude as Algebra.Classes (Int,Integer,Float,Double, Foldable (..), (==), Monoid(..), Ord(..)
-                                  ,Real(..), Enum(..), snd, Rational, Functor(..), Eq(..), Bool(..))
+                                  ,Real(..), Enum(..), snd, Rational, Functor(..), Eq(..), Bool(..), Semigroup(..))
 import qualified Prelude
 import qualified Data.Ratio
 import qualified Data.Map.Strict as M
@@ -29,13 +29,19 @@
 
 instance Additive a => Monoid (Sum a) where
   mempty = Sum zero
-  mappend (Sum x) (Sum y) = Sum (x + y)
+  mappend = (<>)
 
+instance Additive a => Semigroup (Sum a) where
+  (<>) (Sum x) (Sum y) = Sum (x + y)
+
 newtype Product a = Product {fromProduct :: a}
 
+instance Multiplicative a => Semigroup (Product a) where
+  (<>) (Product x) (Product y) = Product (x * y)
+
 instance Multiplicative a => Monoid (Product a) where
   mempty = Product one
-  mappend (Product x) (Product y) = Product (x * y)
+  mappend = (<>)
 
 newtype Exponential a = Exponential {fromExponential :: a}
 
diff --git a/gasp.cabal b/gasp.cabal
--- a/gasp.cabal
+++ b/gasp.cabal
@@ -1,16 +1,20 @@
 name:           gasp
-version:        1.0.1.0
+version:        1.1.0.0
 category:       Algebra
 synopsis:       A framework of algebraic classes
 description:
-  Soon to appear.
+  One algebraic classes framework to rule them all.
 license:        BSD3
 license-file:   LICENSE
 author:         Jean-Philippe Bernardy
 maintainer:     jeanphilippe.bernardy@gmail.com
 Cabal-Version:  >= 1.12
-tested-with:    GHC==7.10.3
+tested-with:    GHC==8.4.1
 build-type:     Simple
+source-repository head
+  type: git
+  location: https://github.com/jyp/gasp
+
 
 library
   default-language: Haskell2010