diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Pedro Tacla Yamada
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/memoization-utils.cabal b/memoization-utils.cabal
new file mode 100644
--- /dev/null
+++ b/memoization-utils.cabal
@@ -0,0 +1,39 @@
+name:                memoization-utils
+version:             0.1.0.0
+synopsis:            Utilities for memoizing functions
+-- description:
+homepage:            http://github.com/yamadapc/haskell-memoization-utils
+license:             MIT
+license-file:        LICENSE
+author:              Pedro Tacla Yamada
+maintainer:          tacla.yamada@gmail.com
+copyright:           Copyright (c) 2015 Pedro Tacla Yamada
+category:            Control
+build-type:          Simple
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     Control.Memoization.Utils
+  build-depends:       base >= 4.7 && < 5
+                     , containers >= 0.5.6.2
+                     , lrucache > 1.2 && < 1.3
+                     , time >= 1.4 && < 1.6
+                     , time-units > 1 && < 2
+  default-language:    Haskell2010
+
+test-suite hspec
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+  build-depends:       base
+                     , time-units > 1 && < 2
+                     , time
+                     , hspec
+                     , memoization-utils
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/yamadapc/haskell-memoization-utils
diff --git a/src/Control/Memoization/Utils.hs b/src/Control/Memoization/Utils.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Memoization/Utils.hs
@@ -0,0 +1,110 @@
+module Control.Memoization.Utils
+    ( memoize
+    , memoizeLru
+    , memoizeTime
+    , constMemoize
+    , constMemoizeTime
+    ) where
+
+import           Control.Concurrent.MVar (newMVar, putMVar, readMVar, swapMVar,
+                                          takeMVar)
+import qualified Data.Cache.LRU.IO       as LRU
+import qualified Data.Map.Strict         as Map
+import           Data.Time               (diffUTCTime, getCurrentTime)
+import           Data.Time.Units         (Millisecond, toMicroseconds)
+
+-- |
+-- Caches function return values so that when the same arguments are provided
+-- to a function, it's not called
+memoize :: Ord a => (a -> IO b) -> IO (a -> IO b)
+memoize action = do
+    mm <- newMVar Map.empty
+    return $ \arg -> do
+        m <- takeMVar mm
+        case Map.lookup arg m of
+            Just ret -> return ret
+            Nothing -> do
+                ret <- action arg
+                putMVar mm (Map.insert arg ret m)
+                return ret
+
+-- |
+-- Version of 'memoize' that uses an LRU cache rather than always keeping results
+-- in memory
+memoizeLru :: Ord a => (Maybe Integer) -> (a -> IO b) -> IO (a -> IO b)
+memoizeLru msize action = do
+    lru <- LRU.newAtomicLRU msize
+    return $ \arg -> do
+        mret <- LRU.lookup arg lru
+        case mret of
+            Just ret -> return ret
+            Nothing -> do
+                ret <- action arg
+                LRU.insert arg ret lru
+                return ret
+
+-- |
+-- Version of 'memoize' keeps results for a certain amount of time
+memoizeTime :: Ord a => Millisecond -> (a -> IO b) -> IO (a -> IO b)
+memoizeTime delay action = do
+    let delayDiff :: Double
+        delayDiff = (fromInteger (toMicroseconds delay)) / 1000000
+    mm <- newMVar Map.empty
+    return $ \arg -> do
+        m <- takeMVar mm
+        case Map.lookup arg m of
+            Just (ret, lastcall) -> do
+                now <- getCurrentTime
+                let diff = fromRational $ toRational $ diffUTCTime now lastcall
+                if diff >= delayDiff
+                    then do
+                        ret' <- action arg
+                        putMVar mm (Map.insert arg (ret', now) m)
+                        return ret'
+                    else do
+                        putMVar mm m
+                        return ret
+            Nothing -> do
+                now <- getCurrentTime
+                ret <- action arg
+                putMVar mm (Map.insert arg (ret, now) m)
+                return ret
+
+-- |
+-- Caches an IO actions result
+constMemoize :: IO b -> IO (IO b)
+constMemoize action = do
+    retmvar <- newMVar Nothing
+    return $ do
+        mret <- readMVar retmvar
+        case mret of
+            Just ret -> return ret
+            Nothing -> do
+                ret <- action
+                _ <- swapMVar retmvar (Just ret)
+                return ret
+
+-- |
+-- Caches an IO actions result for some amount of time
+constMemoizeTime :: Millisecond -> IO b -> IO (IO b)
+constMemoizeTime delay action = do
+    let delayDiff :: Double
+        delayDiff = (fromInteger (toMicroseconds delay)) / 1000000
+    retmvar <- newMVar Nothing
+    return $ do
+        mret <- readMVar retmvar
+        case mret of
+            Just (ret, lastcall) -> do
+                now <- getCurrentTime
+                let diff = fromRational $ toRational $ diffUTCTime now lastcall
+                if diff >= delayDiff
+                    then do
+                        ret' <- action
+                        _ <- swapMVar retmvar (Just (ret, now))
+                        return ret'
+                    else return ret
+            Nothing -> do
+                ret <- action
+                lastcall <- getCurrentTime
+                _ <- swapMVar retmvar (Just (ret, lastcall))
+                return ret
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}