diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,7 @@
+Copyright (c) 2017 Alexander Thiemann
+
+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/README.md b/README.md
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--- /dev/null
+++ b/README.md
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+# Haskell `async-extra` package
+
+[![CircleCI](https://circleci.com/gh/agrafix/async-extra.svg?style=svg)](https://circleci.com/gh/agrafix/async-extra)
+[![Hackage](https://img.shields.io/hackage/v/async-extra.svg)](http://hackage.haskell.org/package/async-extra)
+
+The `async-extra` packages provides useful helper functions extending the `async` package.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
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+import Distribution.Simple
+main = defaultMain
diff --git a/async-extra.cabal b/async-extra.cabal
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--- /dev/null
+++ b/async-extra.cabal
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+name:                async-extra
+version:             0.1.0.0
+synopsis:            Useful concurrent combinators
+description:         Various concurrent combinators
+homepage:            https://github.com/agrafix/async-extra#readme
+license:             MIT
+license-file:        LICENSE
+author:              Alexander Thiemann
+maintainer:          mail@athiemann.net
+copyright:           2017 Alexander Thiemann
+category:            Web
+build-type:          Simple
+extra-source-files:
+                   stack.yaml
+                   README.md
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     Control.Concurrent.Async.Extra
+  build-depends:       base >= 4.8 && < 5,
+                       async,
+                       containers >= 0.5,
+                       deepseq >= 1.4
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/agrafix/async-extra
diff --git a/src/Control/Concurrent/Async/Extra.hs b/src/Control/Concurrent/Async/Extra.hs
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--- /dev/null
+++ b/src/Control/Concurrent/Async/Extra.hs
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+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Control.Concurrent.Async.Extra
+    ( -- * concurrent mapping
+      mapConcurrentlyBounded
+    , mapConcurrentlyBatched
+    , mapConcurrentlyChunks
+      -- * merge strategies
+    , mergeConcatAll
+    )
+where
+
+import Control.Concurrent.Async
+import Control.DeepSeq
+import Control.Exception
+import Data.List
+import Data.Sequence (Seq)
+import qualified Control.Concurrent.QSem as S
+import qualified Data.Foldable as F
+import qualified Data.Sequence as Seq
+
+-- | Span a green thread for each task, but only execute N tasks
+-- concurrently.
+mapConcurrentlyBounded :: Traversable t => Int -> (a -> IO b) -> t a -> IO (t b)
+mapConcurrentlyBounded bound action items =
+    do qs <- S.newQSem bound
+       let wrappedAction x =
+               bracket_ (S.waitQSem qs) (S.signalQSem qs) (action x)
+       mapConcurrently wrappedAction items
+
+-- | Span green threads to perform N (batch size) tasks in one thread
+-- and merge results using provided merge function
+mapConcurrentlyBatched ::
+    (NFData b, Foldable t)
+    => Int -> (Seq (Seq b) -> IO r) -> (a -> IO b) -> t a -> IO r
+mapConcurrentlyBatched batchSize merge action items =
+    do let chunks = chunkList batchSize $ F.toList items
+       r <- mapConcurrently (\x -> force <$> mapM action x) chunks
+       merge r
+
+-- | Split input into N chunks with equal length and work on
+-- each chunk in a dedicated green thread. Then merge results using provided merge function
+mapConcurrentlyChunks ::
+    (NFData b, Foldable t)
+    => Int -> (Seq (Seq b) -> IO r) -> (t a -> Int) -> (a -> IO b) -> t a -> IO r
+mapConcurrentlyChunks chunkCount merge getLength action items =
+    do let listSize = getLength items
+           batchSize :: Double
+           batchSize = fromIntegral listSize / fromIntegral chunkCount
+       mapConcurrentlyBatched (ceiling batchSize) merge action items
+
+-- | Chunk a list into chunks of N elements at maximum
+chunkList :: forall a. Int -> [a] -> Seq (Seq a)
+chunkList chunkSize =
+    go 0 Seq.empty
+    where
+      go :: Int -> Seq a -> [a] -> Seq (Seq a)
+      go !size !chunk q
+          | size == chunkSize =
+                Seq.singleton chunk Seq.>< go 0 Seq.empty q
+          | otherwise =
+                case q of
+                  [] -> Seq.singleton chunk
+                  (x : xs) -> go (size + 1) (chunk Seq.|> x) xs
+
+-- | Merge all chunks by combining to one list
+mergeConcatAll :: Seq (Seq a) -> [a]
+mergeConcatAll = F.toList . foldl' (Seq.><) Seq.empty . F.toList
diff --git a/stack.yaml b/stack.yaml
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--- /dev/null
+++ b/stack.yaml
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+resolver: lts-6.16
+packages:
+- '.'