diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Steve Kollmansberger (c) 2017
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Steve Kollmansberger nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
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+++ b/README.md
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+# Ulid implementation in Haskell
+
+Lexicographically sortable, 128-bit identifier with 48-bit timestamp and 80 random bits.
+Canonically encoded as a 26 character string, as opposed to the 36 character UUID.
+
+Original implementation and spec: https://github.com/alizain/ulid/
+
+
+# Universally Unique Lexicographically Sortable Identifier
+
+UUID can be suboptimal for many uses-cases because:
+
+- It isn't the most character efficient way of encoding 128 bits of randomness
+- UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address
+- UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures
+- UUID v4 provides no other information than randomness which can cause fragmentation in many data structures
+
+Instead, herein is proposed ULID:
+
+- 128-bit compatibility with UUID
+- 1.21e+24 unique ULIDs per millisecond
+- Lexicographically sortable!
+- Canonically encoded as a 26 character string, as opposed to the 36 character UUID
+- Uses Crockford's base32 for better efficiency and readability (5 bits per character)
+- Case insensitive
+- No special characters (URL safe)
+
+
+## Usage
+
+A simple usage example:
+
+````haskell
+module Main where
+
+import           Data.ULID
+
+main :: IO ()
+main = do
+    -- Derive a ULID using the current time and default random number generator
+    ulid1 <- getULID
+    print ulid1
+
+    -- Derive a ULID using a specified time and default random number generator
+    ulid2 <- getULIDTime 1469918176.385 -- POSIX Time, specified to the millisecond
+    print ulid2
+````
+
+As per the spec, it is also possible to use a cryptographically-secure random number generator to contribute the randomness.  However, the programmer must manage the generator on their own. Example:
+
+
+````haskell
+module Main where
+
+import           Data.ULID
+
+import qualified Crypto.Random       as CR
+import qualified Data.ULID.Random    as UR
+import qualified Data.ULID.TimeStamp as TS
+
+main :: IO ()
+main = do     
+    -- This default instantiation may not be sufficiently secure, see the docs 
+    -- https://hackage.haskell.org/package/crypto-api-0.13.2/docs/Crypto-Random.html
+    g <- (CR.newGenIO :: IO CR.SystemRandom)
+
+    -- Generate time stamp from current time
+    t <- TS.getULIDTimeStamp
+    
+    let ulid3 = case UR.mkCryptoULIDRandom g of
+            Left err        -> error $ show err
+            Right (rnd, g2) -> ULID t rnd   -- use g2, etc, to continue generating secure ULIDs
+    print ulid3
+````
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/app/Main.hs b/app/Main.hs
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--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,34 @@
+module Main where
+
+import           Data.ULID
+
+-- These imports only needed for cryptographically secure ULID
+import qualified Crypto.Random       as CR
+import qualified Data.ULID.Random    as UR
+import qualified Data.ULID.TimeStamp as TS
+
+main :: IO ()
+main = do
+     -- Derive a ULID using the current time and default random number generator
+    ulid1 <- getULID
+    print ulid1
+
+    -- Derive a ULID using a specified time and default random number generator
+    ulid2 <- getULIDTime 1469918176.385 -- POSIX Time, specified to the millisecond
+    print ulid2
+
+
+    -- Below only for crypographically secure ULID example
+
+    -- This default instantiation may not be sufficiently secure, see the docs 
+    -- https://hackage.haskell.org/package/crypto-api-0.13.2/docs/Crypto-Random.html
+    g <- (CR.newGenIO :: IO CR.SystemRandom)
+
+    -- Generate time stamp from current time
+    t <- TS.getULIDTimeStamp
+
+    let ulid3 = case UR.mkCryptoULIDRandom g of
+            Left err        -> error $ show err
+            Right (rnd, g2) -> ULID t rnd   -- use g2, etc, to continue generating secure ULIDs
+    print ulid3
+
diff --git a/src/Data/ULID.hs b/src/Data/ULID.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/ULID.hs
@@ -0,0 +1,43 @@
+module Data.ULID (
+    ULID(..),
+    getULIDTime,
+    getULID
+) where
+
+import           Data.Time.Clock.POSIX
+
+import           Data.ULID.Random
+import           Data.ULID.TimeStamp
+
+data ULID = ULID {    
+    timeStamp :: !ULIDTimeStamp,
+    random    :: !ULIDRandom
+    }
+    deriving (Eq)
+
+-- | Derive a ULID using a specified time and default random number generator
+getULIDTime :: POSIXTime    -- ^ The specified UNIX time (seconds) to millisecond precision, e.g. 1469918176.385
+    -> IO ULID
+getULIDTime t = do
+    let t' = mkULIDTimeStamp t
+    r <- getULIDRandom
+    return $ ULID t' r
+
+-- | Derive a ULID using the current time and default random number generator
+getULID :: IO ULID
+getULID = do
+    t <- getULIDTimeStamp
+    r <- getULIDRandom
+    return $ ULID t r
+
+instance Ord ULID where
+    compare (ULID ts1 _) (ULID ts2 _) = compare ts1 ts2
+
+instance Show ULID where
+    show (ULID ts bytes) = (show ts) ++ (show bytes)
+
+instance Read ULID where
+    readsPrec _ str = do
+        (ts, str2) <- reads str
+        (rn, str3) <- reads str2
+        return (ULID ts rn, str3)
diff --git a/src/Data/ULID/Crockford.hs b/src/Data/ULID/Crockford.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/ULID/Crockford.hs
@@ -0,0 +1,19 @@
+module Data.ULID.Crockford (encode, decode) where
+
+import qualified Codec.Crockford as CR
+import           Text.Read
+
+-- source: https://stackoverflow.com/a/29153602
+leftpad m xs = replicate (m - length ys) '0' ++ ys
+    where ys = take m xs
+
+encode :: Int -> Integer -> String
+encode width = (leftpad width).(CR.encode)
+
+decode :: Int -> ReadS Integer
+decode width str  | length str >= width   = let
+                    (crock, remainder) = splitAt width str
+                    in case CR.decode crock of
+                        Nothing -> []
+                        Just c  -> [(c, remainder)]
+                  | otherwise             = []
diff --git a/src/Data/ULID/Random.hs b/src/Data/ULID/Random.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/ULID/Random.hs
@@ -0,0 +1,62 @@
+module Data.ULID.Random (
+    ULIDRandom,
+    mkCryptoULIDRandom,
+    mkULIDRandom,
+    getULIDRandom
+) where
+
+import           Crypto.Random
+import           Data.Binary
+import           Data.Bits
+import qualified Data.ByteString     as BS
+import           Data.List           (foldl', unfoldr)
+import           Data.Word
+import           System.Random
+
+
+import qualified Data.ULID.Crockford as CR
+
+
+newtype ULIDRandom = ULIDRandom BS.ByteString
+    deriving (Eq)
+
+-- | Generate a ULID Random based on a cryptographically secure random number generator. 
+-- | see: https://hackage.haskell.org/package/crypto-api-0.13.2/docs/Crypto-Random.html
+mkCryptoULIDRandom :: CryptoRandomGen g => g -> Either GenError (ULIDRandom, g)
+mkCryptoULIDRandom g = do
+    (b, g2) <- genBytes 10 g
+    return (ULIDRandom b, g2)
+
+-- | Generate a ULID Random based on a standard random number generator.
+-- | see: https://hackage.haskell.org/package/random-1.1/docs/System-Random.html
+mkULIDRandom :: RandomGen g => g -> (ULIDRandom, g)
+mkULIDRandom g = let
+    (g1, g2) = split g
+    genbytes = (BS.pack) . take 10 . randoms
+    in (ULIDRandom $ genbytes g, g2)
+
+-- | Generate a ULID Random based on the global random number generator.
+getULIDRandom :: IO ULIDRandom
+getULIDRandom = fst <$> mkULIDRandom <$> newStdGen -- Note: the call to newStdGen splits the generator, so this is safe to call multiple times
+
+
+-- source: http://hackage.haskell.org/package/binary-0.8.5.1/docs/src/Data-Binary-Class.html#line-311
+--
+-- Fold and unfold an Integer to and from a list of its bytes
+--
+unroll :: Integer -> [Word8]
+unroll = unfoldr step
+  where
+    step 0 = Nothing
+    step i = Just (fromIntegral i, i `shiftR` 8)
+
+roll :: [Word8] -> Integer
+roll = foldl' unstep 0 . reverse
+  where
+    unstep a b = a `shiftL` 8 .|. fromIntegral b
+
+instance Show ULIDRandom where
+    show (ULIDRandom r) =  (CR.encode) 16.roll.(BS.unpack) $ r
+
+instance Read ULIDRandom where
+    readsPrec _ = map (\(c,r)->(ULIDRandom $ (BS.pack) $ unroll c, r)) . (CR.decode) 16
diff --git a/src/Data/ULID/TimeStamp.hs b/src/Data/ULID/TimeStamp.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/ULID/TimeStamp.hs
@@ -0,0 +1,30 @@
+module Data.ULID.TimeStamp (
+    ULIDTimeStamp,
+    mkULIDTimeStamp,
+    getULIDTimeStamp
+) where
+
+import           Data.Time.Clock
+import           Data.Time.Clock.POSIX
+
+import           Data.ULID.Crockford
+
+-- UNIX time in milliseconds
+newtype ULIDTimeStamp = ULIDTimeStamp Integer
+    deriving (Eq, Ord)
+
+-- | Generate a ULID Timestamp based on a specified time
+mkULIDTimeStamp :: POSIXTime -- ^ The specified UNIX time (seconds) to millisecond precision, e.g. 1469918176.385
+    -> ULIDTimeStamp
+mkULIDTimeStamp = ULIDTimeStamp . round . (*1000)
+
+-- | Generate a ULID Timestamp based on current system UNIX time
+getULIDTimeStamp :: IO ULIDTimeStamp
+getULIDTimeStamp = mkULIDTimeStamp <$> getPOSIXTime
+
+instance Show ULIDTimeStamp where
+    show (ULIDTimeStamp i) = encode 10 i
+
+instance Read ULIDTimeStamp where
+    readsPrec _ = map (\(c,r)->(ULIDTimeStamp c, r)) . decode 10
+
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,3 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
+-- see https://github.com/hspec/hspec-example/blob/master/strip.cabal
+-- runhaskell -isrc -itest test/Spec.hs
diff --git a/ulid.cabal b/ulid.cabal
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--- /dev/null
+++ b/ulid.cabal
@@ -0,0 +1,68 @@
+name:                ulid
+version:             0.1.0.0
+synopsis:            Implementation of ULID, lexicographically sortable unique identifiers
+description:         Implementation of alizain's ULID identifier (https://github.com/alizain/ulid ).
+
+                     UUID can be suboptimal for many uses-cases because:
+
+                     It isn't the most character efficient way of encoding 128 bits of randomness
+                     UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address
+                     UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures
+                     UUID v4 provides no other information than randomness which can cause fragmentation in many data structures
+                     Instead, herein is proposed ULID:
+
+                     128-bit compatibility with UUID
+                     1.21e+24 unique ULIDs per millisecond
+                     Lexicographically sortable!
+                     Canonically encoded as a 26 character string, as opposed to the 36 character UUID
+                     Uses Crockford's base32 for better efficiency and readability (5 bits per character)
+                     Case insensitive
+                     No special characters (URL safe)
+homepage:            https://github.com/steven777400/ulid
+license:             BSD3
+license-file:        LICENSE
+author:              Steve Kollmansberger
+maintainer:          steve@kolls.net
+copyright:           2017 Steve Kollmansberger
+category:            Data
+build-type:          Simple
+extra-source-files:  README.md
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     Data.ULID
+                    ,  Data.ULID.Crockford
+                    ,  Data.ULID.Random
+                    ,  Data.ULID.TimeStamp
+  build-depends:       base >= 4.7 && < 5
+                    ,  crockford
+                    ,  time
+                    ,  crypto-api
+                    ,  random
+                    ,  bytestring
+                    ,  binary
+  default-language:    Haskell2010
+
+executable ulid-exe
+  hs-source-dirs:      app
+  main-is:             Main.hs
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
+  build-depends:       base
+                     , ulid
+                     , crypto-api
+  default-language:    Haskell2010
+
+test-suite ulid-test
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+  build-depends:       base
+                     , hspec
+                     , ulid
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/steven777400/ulid.git