diff --git a/ihaskell.cabal b/ihaskell.cabal
index e486a7fc..838d73be 100644
--- a/ihaskell.cabal
+++ b/ihaskell.cabal
@@ -60,9 +60,6 @@ library
                        base64-bytestring    >=1.0,
                        bytestring           >=0.10,
                        cereal               >=0.3,
-                       classy-prelude       >=0.10.5 && <0.11,
-                       chunked-data         ==0.1.*,
-                       mono-traversable     >=0.6,
                        cmdargs              >=0.10,
                        containers           >=0.5,
                        directory            -any,
@@ -74,10 +71,8 @@ library
                        here                 ==1.2.*,
                        hlint                >=1.9 && <2.0,
                        haskell-src-exts     ==1.16.*,
-                       hspec                -any,
                        http-client          == 0.4.*,
                        http-client-tls      == 0.2.*,
-                       HUnit                -any,
                        MissingH             >=1.2,
                        mtl                  >=2.1,
                        parsec               -any,
@@ -89,7 +84,6 @@ library
                        strict               >=0.3,
                        system-argv0         -any,
                        system-filepath      -any,
-                       tar                  -any,
                        text                 >=0.11,
                        transformers         -any,
                        unix                 >= 2.6,
@@ -121,36 +115,72 @@ library
                    IHaskell.Types
                    IHaskell.BrokenPackages
                    Paths_ihaskell
---  other-modules: 
---                   Paths_ihaskell
+  other-modules: 
+                   IHaskellPrelude
+
+  default-extensions:
+      NoImplicitPrelude
+      DoAndIfThenElse
+      OverloadedStrings
+      ExtendedDefaultRules
 
 executable ihaskell
   -- .hs or .lhs file containing the Main module.
-  main-is:             src/Main.hs
+  main-is:             Main.hs
+  hs-source-dirs: src
+  other-modules: 
+                   IHaskellPrelude
   ghc-options: -threaded
   
   -- Other library packages from which modules are imported.
   default-language:    Haskell2010
   build-depends:       
+                       aeson                >=0.7 && < 0.9,
                        base                 >=4.6 && < 4.9,
-                       aeson                >=0.6 && < 0.9,
+                       base64-bytestring    >=1.0,
                        bytestring           >=0.10,
                        cereal               >=0.3,
-                       classy-prelude       >=0.10.5 && <0.11,
-                       chunked-data         ==0.1.*,
-                       mono-traversable     >=0.6,
+                       cmdargs              >=0.10,
                        containers           >=0.5,
                        directory            -any,
-                       ghc                  >=7.6 && < 7.11,
-                       ihaskell             -any,
-                       MissingH             >=1.2,
+                       filepath             -any,
+                       ghc                  >=7.6 || < 7.11,
+                       ghc-parser           >=0.1.7,
+                       ghc-paths            ==0.1.*,
+                       haskeline            -any,
                        here                 ==1.2.*,
-                       text                 -any,
-                       ipython-kernel       >= 0.6.1,
-                       unix                 >= 2.6
+                       hlint                >=1.9 && <2.0,
+                       haskell-src-exts     ==1.16.*,
+                       http-client          == 0.4.*,
+                       http-client-tls      == 0.2.*,
+                       MissingH             >=1.2,
+                       mtl                  >=2.1,
+                       parsec               -any,
+                       process              >=1.1,
+                       random               >=1.0,
+                       shelly               >=1.5,
+                       split                >= 0.2,
+                       stm                  -any,
+                       strict               >=0.3,
+                       system-argv0         -any,
+                       system-filepath      -any,
+                       text                 >=0.11,
+                       transformers         -any,
+                       unix                 >= 2.6,
+                       unordered-containers -any,
+                       utf8-string          -any,
+                       uuid                 >=1.3,
+                       vector               -any,
+                       ipython-kernel       >=0.6.1
   if flag(binPkgDb)
     build-depends:       bin-package-db
 
+  default-extensions:
+      NoImplicitPrelude
+      DoAndIfThenElse
+      OverloadedStrings
+      ExtendedDefaultRules
+
 Test-Suite hspec
     Type: exitcode-stdio-1.0
     Ghc-Options: -threaded
@@ -163,9 +193,6 @@ Test-Suite hspec
         base64-bytestring >=1.0,
         bytestring >=0.10,
         cereal >=0.3,
-        classy-prelude >=0.10.5 && <0.11,
-        chunked-data ==0.1.*,
-        mono-traversable >=0.6,
         cmdargs >=0.10,
         containers >=0.5,
         directory -any,
@@ -190,7 +217,6 @@ Test-Suite hspec
         strict >=0.3,
         system-argv0 -any,
         system-filepath -any,
-        tar -any,
         text >=0.11,
         http-client == 0.4.*,
         http-client-tls == 0.2.*,
diff --git a/src/IHaskell/BrokenPackages.hs b/src/IHaskell/BrokenPackages.hs
index 1eb6cb63..4a1a4664 100644
--- a/src/IHaskell/BrokenPackages.hs
+++ b/src/IHaskell/BrokenPackages.hs
@@ -1,8 +1,13 @@
-{-# LANGUAGE OverloadedStrings, NoImplicitPrelude, FlexibleContexts #-}
+{-# LANGUAGE NoImplicitPrelude, OverloadedStrings, FlexibleContexts #-}
 
 module IHaskell.BrokenPackages (getBrokenPackages) where
 
-import           ClassyPrelude hiding ((<|>))
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 import           Text.Parsec
 import           Text.Parsec.String
@@ -27,7 +32,7 @@ getBrokenPackages = shelly $ do
   -- Get rid of extraneous things
   let rightStart str = startswith "There are problems" str ||
                        startswith "  dependency" str
-      ghcPkgOutput = unlines . filter rightStart . lines $ unpack checkOut
+      ghcPkgOutput = unlines . filter rightStart . lines $ T.unpack checkOut
 
   return $
     case parse (many check) "ghc-pkg output" ghcPkgOutput of
diff --git a/src/IHaskell/Convert.hs b/src/IHaskell/Convert.hs
index ab74b1b5..75334697 100644
--- a/src/IHaskell/Convert.hs
+++ b/src/IHaskell/Convert.hs
@@ -1,6 +1,14 @@
+{-# LANGUAGE NoImplicitPrelude #-}
 -- | Description : mostly reversible conversion between ipynb and lhs 
 module IHaskell.Convert (convert) where
 
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Control.Monad.Identity (Identity(Identity), unless, when)
 import           IHaskell.Convert.Args (ConvertSpec(..), fromJustConvertSpec, toConvertSpec)
 import           IHaskell.Convert.IpynbToLhs (ipynbToLhs)
diff --git a/src/IHaskell/Convert/Args.hs b/src/IHaskell/Convert/Args.hs
index eb58a7a5..0529ca4c 100644
--- a/src/IHaskell/Convert/Args.hs
+++ b/src/IHaskell/Convert/Args.hs
@@ -1,6 +1,14 @@
+{-# LANGUAGE NoImplicitPrelude #-}
 -- | Description: interpret flags parsed by "IHaskell.Flags"
 module IHaskell.Convert.Args (ConvertSpec(..), fromJustConvertSpec, toConvertSpec) where
 
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Control.Applicative ((<$>))
 import           Control.Monad.Identity (Identity(Identity))
 import           Data.Char (toLower)
@@ -17,7 +25,7 @@ data ConvertSpec f =
          { convertToIpynb :: f Bool
          , convertInput :: f FilePath
          , convertOutput :: f FilePath
-         , convertLhsStyle :: f (LhsStyle T.Text)
+         , convertLhsStyle :: f (LhsStyle LT.Text)
          , convertOverwriteFiles :: Bool
          }
 
@@ -28,7 +36,7 @@ fromJustConvertSpec convertSpec = convertSpec
   { convertToIpynb = Identity toIpynb
   , convertInput = Identity inputFile
   , convertOutput = Identity outputFile
-  , convertLhsStyle = Identity $ fromMaybe (T.pack <$> lhsStyleBird) (convertLhsStyle convertSpec)
+  , convertLhsStyle = Identity $ fromMaybe (LT.pack <$> lhsStyleBird) (convertLhsStyle convertSpec)
   }
   where
     toIpynb = fromMaybe (error "Error: direction for conversion unknown")
@@ -63,10 +71,10 @@ mergeArg :: Argument -> ConvertSpec Maybe -> ConvertSpec Maybe
 mergeArg OverwriteFiles convertSpec = convertSpec { convertOverwriteFiles = True }
 mergeArg (ConvertLhsStyle lhsStyle) convertSpec
   | Just previousLhsStyle <- convertLhsStyle convertSpec,
-    previousLhsStyle /= fmap T.pack lhsStyle
+    previousLhsStyle /= fmap LT.pack lhsStyle
   = error $ printf "Conflicting lhs styles requested: <%s> and <%s>" (show lhsStyle)
               (show previousLhsStyle)
-  | otherwise = convertSpec { convertLhsStyle = Just (T.pack <$> lhsStyle) }
+  | otherwise = convertSpec { convertLhsStyle = Just (LT.pack <$> lhsStyle) }
 mergeArg (ConvertFrom inputFile) convertSpec
   | Just previousInputFile <- convertInput convertSpec,
     previousInputFile /= inputFile
diff --git a/src/IHaskell/Convert/IpynbToLhs.hs b/src/IHaskell/Convert/IpynbToLhs.hs
index e390d109..103456f0 100644
--- a/src/IHaskell/Convert/IpynbToLhs.hs
+++ b/src/IHaskell/Convert/IpynbToLhs.hs
@@ -1,66 +1,71 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NoImplicitPrelude, OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
 module IHaskell.Convert.IpynbToLhs (ipynbToLhs) where
 
-import           Control.Applicative ((<$>))
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Data.Aeson (decode, Object, Value(Array, Object, String))
-import qualified Data.ByteString.Lazy as L (readFile)
-import qualified Data.HashMap.Strict as M (lookup)
-import           Data.Maybe (fromMaybe)
 import           Data.Monoid ((<>), Monoid(mempty))
-import qualified Data.Text.Lazy as T (concat, fromStrict, Text, unlines)
-import qualified Data.Text.Lazy.IO as T (writeFile)
 import           Data.Vector (Vector)
+import           Data.HashMap.Strict (lookup)
+
+import qualified Data.Text.Lazy.IO as LTIO
 import qualified Data.Vector as V (map, mapM, toList)
+
 import           IHaskell.Flags (LhsStyle(..))
 
-ipynbToLhs :: LhsStyle T.Text
+ipynbToLhs :: LhsStyle LText
            -> FilePath -- ^ the filename of an ipython notebook
            -> FilePath -- ^ the filename of the literate haskell to write
            -> IO ()
 ipynbToLhs sty from to = do
-  Just (js :: Object) <- decode <$> L.readFile from
-  case M.lookup "cells" js of
+  Just (js :: Object) <- decode <$> LBS.readFile from
+  case lookup "cells" js of
     Just (Array cells) ->
-      T.writeFile to $ T.unlines $ V.toList $ V.map (\(Object y) -> convCell sty y) cells
+      LTIO.writeFile to $ LT.unlines $ V.toList $ V.map (\(Object y) -> convCell sty y) cells
     _ -> error "IHaskell.Convert.ipynbTolhs: json does not follow expected schema"
 
-concatWithPrefix :: T.Text -- ^ the prefix to add to every line
+concatWithPrefix :: LT.Text -- ^ the prefix to add to every line
                  -> Vector Value          -- ^ a json array of text lines
-                 -> Maybe T.Text
-concatWithPrefix p arr = T.concat . map (p <>) . V.toList <$> V.mapM toStr arr
+                 -> Maybe LT.Text
+concatWithPrefix p arr = LT.concat . map (p <>) . V.toList <$> V.mapM toStr arr
 
-toStr :: Value -> Maybe T.Text
-toStr (String x) = Just (T.fromStrict x)
+toStr :: Value -> Maybe LT.Text
+toStr (String x) = Just (LT.fromStrict x)
 toStr _ = Nothing
 
 -- | @convCell sty cell@ converts a single cell in JSON into text suitable for the type of lhs file
 -- described by the @sty@
-convCell :: LhsStyle T.Text -> Object -> T.Text
+convCell :: LhsStyle LT.Text -> Object -> LT.Text
 convCell _sty object
-  | Just (String "markdown") <- M.lookup "cell_type" object,
-    Just (Array xs) <- M.lookup "source" object,
+  | Just (String "markdown") <- lookup "cell_type" object,
+    Just (Array xs) <- lookup "source" object,
     ~(Just s) <- concatWithPrefix "" xs
   = s
 convCell sty object
-  | Just (String "code") <- M.lookup "cell_type" object,
-    Just (Array i) <- M.lookup "source" object,
-    Just (Array o) <- M.lookup "outputs" object,
+  | Just (String "code") <- lookup "cell_type" object,
+    Just (Array i) <- lookup "source" object,
+    Just (Array o) <- lookup "outputs" object,
     ~(Just i) <- concatWithPrefix (lhsCodePrefix sty) i,
     o <- fromMaybe mempty (convOutputs sty o)
   = "\n" <>
     lhsBeginCode sty <> i <> lhsEndCode sty <> "\n" <> o <> "\n"
 convCell _ _ = "IHaskell.Convert.convCell: unknown cell"
 
-convOutputs :: LhsStyle T.Text
+convOutputs :: LhsStyle LT.Text
             -> Vector Value -- ^ JSON array of output lines containing text or markup
-            -> Maybe T.Text
+            -> Maybe LT.Text
 convOutputs sty array = do
   outputLines <- V.mapM (getTexts (lhsOutputPrefix sty)) array
-  return $ lhsBeginOutput sty <> T.concat (V.toList outputLines) <> lhsEndOutput sty
+  return $ lhsBeginOutput sty <> LT.concat (V.toList outputLines) <> lhsEndOutput sty
 
-getTexts :: T.Text -> Value -> Maybe T.Text
+getTexts :: LT.Text -> Value -> Maybe LT.Text
 getTexts p (Object object)
-  | Just (Array text) <- M.lookup "text" object = concatWithPrefix p text
+  | Just (Array text) <- lookup "text" object = concatWithPrefix p text
 getTexts _ _ = Nothing
diff --git a/src/IHaskell/Convert/LhsToIpynb.hs b/src/IHaskell/Convert/LhsToIpynb.hs
index dde1d66f..5ebca74c 100644
--- a/src/IHaskell/Convert/LhsToIpynb.hs
+++ b/src/IHaskell/Convert/LhsToIpynb.hs
@@ -1,24 +1,26 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NoImplicitPrelude, OverloadedStrings #-}
 {-# LANGUAGE CPP #-}
 
 module IHaskell.Convert.LhsToIpynb (lhsToIpynb) where
 
-import           Control.Applicative ((<$>))
-import           Control.Monad (mplus)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Data.Aeson ((.=), encode, object, Value(Array, Bool, Number, String, Null))
-import qualified Data.ByteString.Lazy as L (writeFile)
 import           Data.Char (isSpace)
-import           Data.Monoid (Monoid(mempty))
-import qualified Data.Text as TS (Text)
-import qualified Data.Text.Lazy as T (dropWhile, lines, stripPrefix, Text, toStrict, snoc, strip)
-import qualified Data.Text.Lazy.IO as T (readFile)
 import qualified Data.Vector as V (fromList, singleton)
+import qualified Data.List as List
+
 import           IHaskell.Flags (LhsStyle(LhsStyle))
 
-lhsToIpynb :: LhsStyle T.Text -> FilePath -> FilePath -> IO ()
+lhsToIpynb :: LhsStyle LText -> FilePath -> FilePath -> IO ()
 lhsToIpynb sty from to = do
-  classed <- classifyLines sty . T.lines <$> T.readFile from
-  L.writeFile to . encode . encodeCells $ groupClassified classed
+  classed <- classifyLines sty . LT.lines . LT.pack <$> readFile from
+  LBS.writeFile to . encode . encodeCells $ groupClassified classed
 
 data CellLine a = CodeLine a
                 | OutputLine a
@@ -50,40 +52,39 @@ data Cell a = Code a a
             | Markdown a
   deriving Show
 
-encodeCells :: [Cell [T.Text]] -> Value
+encodeCells :: [Cell [LText]] -> Value
 encodeCells xs = object $
-  ["cells" .= Array (V.fromList (map cellToVal xs))]
-  ++ boilerplate
+  "cells" .= Array (V.fromList (map cellToVal xs)) : boilerplate
 
-cellToVal :: Cell [T.Text] -> Value
-cellToVal (Code i o) = object $
-  [ "cell_type" .= String "code"
-  , "execution_count" .= Null
-  , "metadata" .= object ["collapsed" .= Bool False]
-  , "source" .= arrayFromTxt i
-  , "outputs" .= Array
-                   (V.fromList
-                      ([object
-                          [ "text" .= arrayFromTxt o
-                          , "metadata" .= object []
-                          , "output_type" .= String "display_data"
-                          ] | _ <- take 1 o]))
-  ]
-cellToVal (Markdown txt) = object $
+cellToVal :: Cell [LText] -> Value
+cellToVal (Code i o) = object
+                         [ "cell_type" .= String "code"
+                         , "execution_count" .= Null
+                         , "metadata" .= object ["collapsed" .= Bool False]
+                         , "source" .= arrayFromTxt i
+                         , "outputs" .= Array
+                                          (V.fromList
+                                             [object
+                                                [ "text" .= arrayFromTxt o
+                                                , "metadata" .= object []
+                                                , "output_type" .= String "display_data"
+                                                ] | _ <- take 1 o])
+                         ]
+cellToVal (Markdown txt) = object
   [ "cell_type" .= String "markdown"
   , "metadata" .= object ["hidden" .= Bool False]
   , "source" .= arrayFromTxt txt
   ]
 
 -- | arrayFromTxt makes a JSON array of string s
-arrayFromTxt :: [T.Text] -> Value
+arrayFromTxt :: [LText] -> Value
 arrayFromTxt i = Array (V.fromList $ map stringify i)
   where
-    stringify = String . T.toStrict . flip T.snoc '\n'
+    stringify = String . LT.toStrict . flip LT.snoc '\n'
 
 -- | ihaskell needs this boilerplate at the upper level to interpret the json describing cells and
 -- output correctly.
-boilerplate :: [(TS.Text, Value)]
+boilerplate :: [(T.Text, Value)]
 boilerplate =
   ["metadata" .= object [kernelspec, lang], "nbformat" .= Number 4, "nbformat_minor" .= Number 0]
   where
@@ -94,18 +95,18 @@ boilerplate =
                                    ]
     lang = "language_info" .= object ["name" .= String "haskell", "version" .= String VERSION_ghc]
 
-groupClassified :: [CellLine T.Text] -> [Cell [T.Text]]
+groupClassified :: [CellLine LText] -> [Cell [LText]]
 groupClassified (CodeLine a:x)
-  | (c, x) <- span isCode x,
-    (_, x) <- span isEmptyMD x,
-    (o, x) <- span isOutput x
+  | (c, x) <- List.span isCode x,
+    (_, x) <- List.span isEmptyMD x,
+    (o, x) <- List.span isOutput x
   = Code (a : map untag c) (map untag o) : groupClassified x
 groupClassified (MarkdownLine a:x)
-  | (m, x) <- span isMD x = Markdown (a : map untag m) : groupClassified x
+  | (m, x) <- List.span isMD x = Markdown (a : map untag m) : groupClassified x
 groupClassified (OutputLine a:x) = Markdown [a] : groupClassified x
 groupClassified [] = []
 
-classifyLines :: LhsStyle T.Text -> [T.Text] -> [CellLine T.Text]
+classifyLines :: LhsStyle LText -> [LText] -> [CellLine LText]
 classifyLines sty@(LhsStyle c o _ _ _ _) (l:ls) =
   case (sp c, sp o) of
     (Just a, Nothing)  -> CodeLine a : classifyLines sty ls
@@ -113,9 +114,9 @@ classifyLines sty@(LhsStyle c o _ _ _ _) (l:ls) =
     (Nothing, Nothing) -> MarkdownLine l : classifyLines sty ls
     _                  -> error "IHaskell.Convert.classifyLines"
   where
-    sp x = T.stripPrefix (dropSpace x) (dropSpace l) `mplus` blankCodeLine x
-    blankCodeLine x = if T.strip x == T.strip l
+    sp x = LT.stripPrefix (dropSpace x) (dropSpace l) `mplus` blankCodeLine x
+    blankCodeLine x = if LT.strip x == LT.strip l
                         then Just ""
                         else Nothing
-    dropSpace = T.dropWhile isSpace
+    dropSpace = LT.dropWhile isSpace
 classifyLines _ [] = []
diff --git a/src/IHaskell/Display.hs b/src/IHaskell/Display.hs
index 67d1bc53..2f5e7f70 100644
--- a/src/IHaskell/Display.hs
+++ b/src/IHaskell/Display.hs
@@ -48,18 +48,26 @@ module IHaskell.Display (
     Widget(..),
     ) where
 
-import           ClassyPrelude
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Data.Serialize as Serialize
-import           Data.ByteString hiding (map, pack)
 import           Data.String.Utils (rstrip)
 import qualified Data.ByteString.Base64 as Base64
-import qualified Data.ByteString.Char8 as Char
 import           Data.Aeson (Value)
 import           System.Directory (getTemporaryDirectory, setCurrentDirectory)
 
+import           Control.Concurrent.STM (atomically)
+import           Control.Exception (try)
 import           Control.Concurrent.STM.TChan
 import           System.IO.Unsafe (unsafePerformIO)
 
+import qualified Data.Text.Encoding as E
+
 import           IHaskell.Types
 
 type Base64 = Text
@@ -92,23 +100,23 @@ many = ManyDisplay
 
 -- | Generate a plain text display.
 plain :: String -> DisplayData
-plain = DisplayData PlainText . pack . rstrip
+plain = DisplayData PlainText . T.pack . rstrip
 
 -- | Generate an HTML display.
 html :: String -> DisplayData
-html = DisplayData MimeHtml . pack
+html = DisplayData MimeHtml . T.pack
 
 -- | Generate an SVG display.
 svg :: String -> DisplayData
-svg = DisplayData MimeSvg . pack
+svg = DisplayData MimeSvg . T.pack
 
 -- | Generate a LaTeX display.
 latex :: String -> DisplayData
-latex = DisplayData MimeLatex . pack
+latex = DisplayData MimeLatex . T.pack
 
 -- | Generate a Javascript display.
 javascript :: String -> DisplayData
-javascript = DisplayData MimeJavascript . pack
+javascript = DisplayData MimeJavascript . T.pack
 
 -- | Generate a PNG display of the given width and height. Data must be provided in a Base64 encoded
 -- manner, suitable for embedding into HTML. The @base64@ function may be used to encode data into
@@ -124,11 +132,11 @@ jpg width height = DisplayData (MimeJpg width height)
 
 -- | Convert from a string into base 64 encoded data.
 encode64 :: String -> Base64
-encode64 str = base64 $ Char.pack str
+encode64 str = base64 $ CBS.pack str
 
 -- | Convert from a ByteString into base 64 encoded data.
 base64 :: ByteString -> Base64
-base64 = decodeUtf8 . Base64.encode
+base64 = E.decodeUtf8 . Base64.encode
 
 -- | For internal use within IHaskell. Serialize displays to a ByteString.
 serializeDisplay :: Display -> ByteString
diff --git a/src/IHaskell/Eval/Completion.hs b/src/IHaskell/Eval/Completion.hs
index 57b53cbd..19417c8b 100644
--- a/src/IHaskell/Eval/Completion.hs
+++ b/src/IHaskell/Eval/Completion.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, NoImplicitPrelude, OverloadedStrings, DoAndIfThenElse #-}
+{-# LANGUAGE NoImplicitPrelude, CPP, OverloadedStrings, DoAndIfThenElse #-}
 {-# LANGUAGE TypeFamilies, FlexibleContexts #-}
 
 {- |
@@ -13,7 +13,12 @@ This has a limited amount of context sensitivity. It distinguishes between four
 -}
 module IHaskell.Eval.Completion (complete, completionTarget, completionType, CompletionType(..)) where
 
-import           ClassyPrelude hiding (init, last, head, liftIO)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 import           Control.Applicative ((<$>))
 import           Data.ByteString.UTF8 hiding (drop, take, lines, length)
@@ -34,11 +39,12 @@ import           DynFlags
 import           GhcMonad
 import           PackageConfig
 import           Outputable (showPpr)
+import           MonadUtils (MonadIO)
 
 
 import           System.Directory
 import           System.FilePath
-import           MonadUtils (MonadIO)
+import           Control.Exception (try)
 
 import           System.Console.Haskeline.Completion
 
@@ -155,7 +161,7 @@ getTrueModuleName name = do
       onlyImportDecl _ = Nothing
 
   -- Get all imports that we use.
-  imports <- ClassyPrelude.catMaybes <$> map onlyImportDecl <$> getContext
+  imports <- catMaybes <$> map onlyImportDecl <$> getContext
 
   -- Find the ones that have a qualified name attached. If this name isn't one of them, it already is
   -- the true name.
diff --git a/src/IHaskell/Eval/Evaluate.hs b/src/IHaskell/Eval/Evaluate.hs
index 895474a6..545f44db 100644
--- a/src/IHaskell/Eval/Evaluate.hs
+++ b/src/IHaskell/Eval/Evaluate.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE DoAndIfThenElse, NoOverloadedStrings, TypeSynonymInstances, GADTs, CPP #-}
+{-# LANGUAGE NoImplicitPrelude, DoAndIfThenElse, NoOverloadedStrings, TypeSynonymInstances, GADTs, CPP #-}
 
 {- | Description : Wrapper around GHC API, exposing a single `evaluate` interface that runs
                    a statement, declaration, import, or directive.
@@ -15,7 +15,13 @@ module IHaskell.Eval.Evaluate (
     formatType,
     ) where
 
-import           ClassyPrelude hiding (init, last, liftIO, head, hGetContents, tail, try)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Control.Concurrent (forkIO, threadDelay)
 import           Prelude (putChar, head, tail, last, init, (!!))
 import           Data.List.Utils
@@ -68,8 +74,6 @@ import           FastString
 import           Bag
 import           ErrUtils (errMsgShortDoc, errMsgExtraInfo)
 
-import qualified System.IO.Strict as StrictIO
-
 import           IHaskell.Types
 import           IHaskell.IPython
 import           IHaskell.Eval.Parser
@@ -403,7 +407,7 @@ evalCommand _ (Module contents) state = wrapExecution state $ do
       filename = last namePieces ++ ".hs"
   liftIO $ do
     createDirectoryIfMissing True directory
-    writeFile (fpFromString $ directory ++ filename) contents
+    writeFile (directory ++ filename) contents
 
   -- Clear old modules of this name
   let modName = intercalate "." namePieces
@@ -565,7 +569,7 @@ evalCommand _ (Directive LoadFile names) state = wrapExecution state $ do
                 let filename = if endswith ".hs" name
                                  then name
                                  else name ++ ".hs"
-                contents <- readFile $ fpFromString filename
+                contents <- liftIO $ readFile filename
                 modName <- intercalate "." <$> getModuleName contents
                 doLoadModule filename modName
   return (ManyDisplay displays)
@@ -1016,7 +1020,7 @@ doLoadModule name modName = do
     setSessionDynFlags
       flags
         { hscTarget = objTarget flags
-        , log_action = \dflags sev srcspan ppr msg -> modifyIORef errRef (showSDoc flags msg :)
+        , log_action = \dflags sev srcspan ppr msg -> modifyIORef' errRef (showSDoc flags msg :)
         }
 
     -- Load the new target.
diff --git a/src/IHaskell/Eval/Hoogle.hs b/src/IHaskell/Eval/Hoogle.hs
index 1ac55f3b..7308907e 100644
--- a/src/IHaskell/Eval/Hoogle.hs
+++ b/src/IHaskell/Eval/Hoogle.hs
@@ -8,16 +8,19 @@ module IHaskell.Eval.Hoogle (
     HoogleResult,
     ) where
 
-import           ClassyPrelude hiding (last, span, div)
-import           Text.Printf
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Network.HTTP.Client
 import           Network.HTTP.Client.TLS
 import           Data.Aeson
 import           Data.String.Utils
-import           Data.List (elemIndex, (!!), last)
+import         qualified Data.List as List
 import           Data.Char (isAscii, isAlphaNum)
-import qualified Data.ByteString.Lazy.Char8 as Char
-import qualified Prelude as P
 
 
 import           IHaskell.IPython
@@ -52,11 +55,8 @@ instance FromJSON HoogleResponse where
 query :: String -> IO (Either String String)
 query str = do
   request <- parseUrl $ queryUrl $ urlEncode str
-  response <- try $ withManager tlsManagerSettings $ httpLbs request
-  return $
-    case response of
-      Left err   -> Left $ show (err :: SomeException)
-      Right resp -> Right $ Char.unpack $ responseBody resp
+  catch (Right . CBS.unpack . LBS.toStrict . responseBody <$> withManager tlsManagerSettings (httpLbs request))
+        (\e -> return $ Left $ show (e :: SomeException))
 
   where
     queryUrl :: String -> String
@@ -66,25 +66,25 @@ query str = do
 urlEncode :: String -> String
 urlEncode [] = []
 urlEncode (ch:t)
-  | (isAscii ch && isAlphaNum ch) || ch `P.elem` ("-_.~" :: String) = ch : urlEncode t
-  | not (isAscii ch) = P.foldr escape (urlEncode t) (eightBs [] (P.fromEnum ch))
-  | otherwise = escape (P.fromEnum ch) (urlEncode t)
+  | (isAscii ch && isAlphaNum ch) || ch `elem` ("-_.~" :: String) = ch : urlEncode t
+  | not (isAscii ch) = foldr escape (urlEncode t) (eightBs [] (fromEnum ch))
+  | otherwise = escape (fromEnum ch) (urlEncode t)
   where
     escape :: Int -> String -> String
-    escape b rs = '%' : showH (b `P.div` 16) (showH (b `mod` 16) rs)
+    escape b rs = '%' : showH (b `div` 16) (showH (b `mod` 16) rs)
 
     showH :: Int -> String -> String
     showH x xs
       | x <= 9 = toEnum (o_0 + x) : xs
       | otherwise = toEnum (o_A + (x - 10)) : xs
       where
-        o_0 = P.fromEnum '0'
-        o_A = P.fromEnum 'A'
+        o_0 = fromEnum '0'
+        o_A = fromEnum 'A'
 
     eightBs :: [Int] -> Int -> [Int]
     eightBs acc x
       | x <= 255 = x : acc
-      | otherwise = eightBs ((x `mod` 256) : acc) (x `P.div` 256)
+      | otherwise = eightBs ((x `mod` 256) : acc) (x `div` 256)
 
 -- | Search for a query on Hoogle. Return all search results.
 search :: String -> IO [HoogleResult]
@@ -94,7 +94,7 @@ search string = do
     case response of
       Left err -> [NoResult err]
       Right json ->
-        case eitherDecode $ Char.pack json of
+        case eitherDecode $ LBS.fromStrict$ CBS.pack json of
           Left err -> [NoResult err]
           Right results ->
             case map SearchResult results of
@@ -216,7 +216,7 @@ renderSelf string loc
 
 renderDocs :: String -> String
 renderDocs doc =
-  let groups = groupBy bothAreCode $ lines doc
+  let groups = List.groupBy bothAreCode $ lines doc
       nonull = filter (not . null . strip)
       bothAreCode s1 s2 =
                            startswith ">" (strip s1) &&
@@ -224,28 +224,28 @@ renderDocs doc =
       isCode (s:_) = startswith ">" $ strip s
       makeBlock lines =
                          if isCode lines
-                           then div "hoogle-code" $ unlines $ nonull lines
-                           else div "hoogle-text" $ unlines $ nonull lines
-  in div "hoogle-doc" $ unlines $ map makeBlock groups
+                           then div' "hoogle-code" $ unlines $ nonull lines
+                           else div' "hoogle-text" $ unlines $ nonull lines
+  in div' "hoogle-doc" $ unlines $ map makeBlock groups
 
 extractPackageName :: String -> Maybe String
 extractPackageName link = do
   let pieces = split "/" link
-  archiveLoc <- elemIndex "archive" pieces
-  latestLoc <- elemIndex "latest" pieces
+  archiveLoc <- List.elemIndex "archive" pieces
+  latestLoc <- List.elemIndex "latest" pieces
   guard $ latestLoc - archiveLoc == 2
-  return $ pieces !! (latestLoc - 1)
+  return $ pieces List.!! (latestLoc - 1)
 
 extractModuleName :: String -> Maybe String
 extractModuleName link = do
   let pieces = split "/" link
   guard $ not $ null pieces
-  let html = last pieces
+  let html = fromJust $ lastMay pieces
       mod = replace "-" "." $ takeWhile (/= '.') html
   return mod
 
-div :: String -> String -> String
-div = printf "<div class='%s'>%s</div>"
+div' :: String -> String -> String
+div' = printf "<div class='%s'>%s</div>"
 
 span :: String -> String -> String
 span = printf "<span class='%s'>%s</span>"
diff --git a/src/IHaskell/Eval/Info.hs b/src/IHaskell/Eval/Info.hs
index 499170a8..dcb87889 100644
--- a/src/IHaskell/Eval/Info.hs
+++ b/src/IHaskell/Eval/Info.hs
@@ -3,7 +3,12 @@
 {- | Description : Inspect type and function information and documentation.  -}
 module IHaskell.Eval.Info (info) where
 
-import           ClassyPrelude hiding (liftIO)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 import           IHaskell.Eval.Evaluate (typeCleaner, Interpreter)
 
diff --git a/src/IHaskell/Eval/Inspect.hs b/src/IHaskell/Eval/Inspect.hs
index d21f2562..b0fd4962 100644
--- a/src/IHaskell/Eval/Inspect.hs
+++ b/src/IHaskell/Eval/Inspect.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, NoImplicitPrelude, OverloadedStrings, DoAndIfThenElse, FlexibleContexts #-}
+{-# LANGUAGE NoImplicitPrelude, CPP, OverloadedStrings, DoAndIfThenElse, FlexibleContexts #-}
 
 {- |
 Description:    Generates inspections when asked for by the frontend.
@@ -6,7 +6,13 @@ Description:    Generates inspections when asked for by the frontend.
 -}
 module IHaskell.Eval.Inspect (inspect) where
 
-import           ClassyPrelude
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import qualified Prelude as P
 
 import           Data.List.Split (splitOn)
diff --git a/src/IHaskell/Eval/Lint.hs b/src/IHaskell/Eval/Lint.hs
index 53700df9..599ec2de 100644
--- a/src/IHaskell/Eval/Lint.hs
+++ b/src/IHaskell/Eval/Lint.hs
@@ -1,10 +1,16 @@
-{-# LANGUAGE FlexibleContexts, NoImplicitPrelude, QuasiQuotes, ViewPatterns #-}
+{-# LANGUAGE NoImplicitPrelude, FlexibleContexts, QuasiQuotes, ViewPatterns #-}
 
 module IHaskell.Eval.Lint (lint) where
 
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Data.String.Utils (replace, startswith, strip, split)
 import           Prelude (head, tail, last)
-import           ClassyPrelude hiding (last)
 import           Control.Monad
 import           Data.List (findIndex)
 import           Text.Printf
diff --git a/src/IHaskell/Eval/ParseShell.hs b/src/IHaskell/Eval/ParseShell.hs
index c6efcabc..cf03bb49 100644
--- a/src/IHaskell/Eval/ParseShell.hs
+++ b/src/IHaskell/Eval/ParseShell.hs
@@ -1,10 +1,16 @@
+{-# LANGUAGE NoImplicitPrelude #-}
 -- | This module splits a shell command line into a list of strings,
 --   one for each command / filename
 module IHaskell.Eval.ParseShell (parseShell) where
 
-import           Prelude hiding (words)
-import           Text.ParserCombinators.Parsec hiding (manyTill)
-import           Control.Applicative hiding ((<|>), many, optional)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
+import           Text.ParserCombinators.Parsec
 
 eol :: Parser Char
 eol = oneOf "\n\r" <?> "end of line"
@@ -12,18 +18,18 @@ eol = oneOf "\n\r" <?> "end of line"
 quote :: Parser Char
 quote = char '\"'
 
--- | @manyTill p end@ from hidden @manyTill@ in that it appends the result of @end@
-manyTill :: Parser a -> Parser [a] -> Parser [a]
-manyTill p end = scan
+-- | @manyTillEnd p end@ from normal @manyTill@ in that it appends the result of @end@
+manyTillEnd :: Parser a -> Parser [a] -> Parser [a]
+manyTillEnd p end = scan
   where
     scan = end <|> do
              x <- p
              xs <- scan
              return $ x : xs
 
-manyTill1 p end = do
+manyTillEnd1 p end = do
   x <- p
-  xs <- manyTill p end
+  xs <- manyTillEnd p end
   return $ x : xs
 
 unescapedChar :: Parser Char -> Parser String
@@ -34,9 +40,9 @@ unescapedChar p = try $ do
 
 quotedString = do
   quote <?> "expected starting quote"
-  (manyTill anyChar (unescapedChar quote) <* quote) <?> "unexpected in quoted String "
+  (manyTillEnd anyChar (unescapedChar quote) <* quote) <?> "unexpected in quoted String "
 
-unquotedString = manyTill1 anyChar end
+unquotedString = manyTillEnd1 anyChar end
   where
     end = unescapedChar space
           <|> (lookAhead eol >> return [])
@@ -47,14 +53,14 @@ separator :: Parser String
 separator = many1 space <?> "separator"
 
 -- | Input must terminate in a space character (like a \n)
-words :: Parser [String]
-words = try (eof *> return []) <|> do
+shellWords :: Parser [String]
+shellWords = try (eof *> return []) <|> do
           x <- word
           rest1 <- lookAhead (many anyToken)
           ss <- separator
           rest2 <- lookAhead (many anyToken)
-          xs <- words
+          xs <- shellWords
           return $ x : xs
 
 parseShell :: String -> Either ParseError [String]
-parseShell string = parse words "shell" (string ++ "\n")
+parseShell string = parse shellWords "shell" (string ++ "\n")
diff --git a/src/IHaskell/Eval/Parser.hs b/src/IHaskell/Eval/Parser.hs
index c408ff8b..23c21f78 100644
--- a/src/IHaskell/Eval/Parser.hs
+++ b/src/IHaskell/Eval/Parser.hs
@@ -15,7 +15,12 @@ module IHaskell.Eval.Parser (
     PragmaType(..),
     ) where
 
-import           ClassyPrelude hiding (head, liftIO, maximumBy)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 import           Data.List (maximumBy, inits)
 import           Data.String.Utils (startswith, strip, split)
diff --git a/src/IHaskell/Eval/Util.hs b/src/IHaskell/Eval/Util.hs
index 54baebf0..13976fb4 100644
--- a/src/IHaskell/Eval/Util.hs
+++ b/src/IHaskell/Eval/Util.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, NoImplicitPrelude #-}
+{-# LANGUAGE NoImplicitPrelude, CPP #-}
 
 module IHaskell.Eval.Util (
     -- * Initialization
@@ -23,7 +23,12 @@ module IHaskell.Eval.Util (
     pprLanguages,
     ) where
 
-import           ClassyPrelude hiding ((<>))
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 -- GHC imports.
 import           DynFlags
@@ -34,7 +39,6 @@ import           HsImpExp
 import           HscTypes
 import           InteractiveEval
 import           Module
-import           Outputable
 import           Packages
 import           RdrName
 import           NameSet
@@ -44,6 +48,7 @@ import           InstEnv (ClsInst(..))
 import           Unify (tcMatchTys)
 import           VarSet (mkVarSet)
 import qualified Pretty
+import qualified Outputable as O
 
 import           Control.Monad (void)
 import           Data.Function (on)
@@ -80,15 +85,15 @@ flagSpecFlag (_, flag, _) = flag
 -- | Pretty-print dynamic flags (taken from 'InteractiveUI' module of `ghc-bin`)
 pprDynFlags :: Bool       -- ^ Whether to include flags which are on by default
             -> DynFlags
-            -> SDoc
+            -> O.SDoc
 pprDynFlags show_all dflags =
-  vcat
-    [ text "GHCi-specific dynamic flag settings:" $$
-      nest 2 (vcat (map (setting opt) ghciFlags))
-    , text "other dynamic, non-language, flag settings:" $$
-      nest 2 (vcat (map (setting opt) others))
-    , text "warning settings:" $$
-      nest 2 (vcat (map (setting wopt) DynFlags.fWarningFlags))
+  O.vcat
+    [ O.text "GHCi-specific dynamic flag settings:" O.$$
+      O.nest 2 (O.vcat (map (setting opt) ghciFlags))
+    , O.text "other dynamic, non-language, flag settings:" O.$$
+      O.nest 2 (O.vcat (map (setting opt) others))
+    , O.text "warning settings:" O.$$
+      O.nest 2 (O.vcat (map (setting wopt) DynFlags.fWarningFlags))
     ]
   where
 
@@ -98,9 +103,9 @@ pprDynFlags show_all dflags =
     opt = dopt
 #endif
     setting test flag
-      | quiet = empty
-      | is_on = fstr name
-      | otherwise = fnostr name
+      | quiet = O.empty :: O.SDoc
+      | is_on = fstr name :: O.SDoc
+      | otherwise = fnostr name :: O.SDoc
       where
         name = flagSpecName flag
         f = flagSpecFlag flag
@@ -109,9 +114,9 @@ pprDynFlags show_all dflags =
     
     default_dflags = defaultDynFlags (settings dflags)
     
-    fstr str = text "-f" <> text str
-    
-    fnostr str = text "-fno-" <> text str
+    fstr, fnostr :: String -> O.SDoc
+    fstr str = O.text "-f" O.<> O.text str
+    fnostr str = O.text "-fno-" O.<> O.text str
     
     (ghciFlags, others) = partition (\f -> flagSpecFlag f `elem` flgs) DynFlags.fFlags
     
@@ -129,22 +134,22 @@ flgs3 = [Opt_PrintBindResult, Opt_BreakOnException, Opt_BreakOnError, Opt_PrintE
 -- `ghc-bin`)
 pprLanguages :: Bool      -- ^ Whether to include flags which are on by default
              -> DynFlags
-             -> SDoc
+             -> O.SDoc
 pprLanguages show_all dflags =
-  vcat
-    [text "base language is: " <>
+  O.vcat
+    [O.text "base language is: " O.<>
      case language dflags of
-       Nothing          -> text "Haskell2010"
-       Just Haskell98   -> text "Haskell98"
-       Just Haskell2010 -> text "Haskell2010", (if show_all
-                                                  then text "all active language options:"
-                                                  else text "with the following modifiers:") $$
-                                               nest 2 (vcat (map (setting xopt) DynFlags.xFlags))]
+       Nothing          -> O.text "Haskell2010"
+       Just Haskell98   -> O.text "Haskell98"
+       Just Haskell2010 -> O.text "Haskell2010", (if show_all
+                                                  then O.text "all active language options:"
+                                                  else O.text "with the following modifiers:") O.$$
+                                               O.nest 2 (O.vcat (map (setting xopt) DynFlags.xFlags))]
   where
     setting test flag
-      | quiet = empty
-      | is_on = text "-X" <> text name
-      | otherwise = text "-XNo" <> text name
+      | quiet = O.empty
+      | is_on = O.text "-X" O.<> O.text name
+      | otherwise = O.text "-XNo" O.<> O.text name
       where
         name = flagSpecName flag
         f = flagSpecFlag flag
@@ -196,13 +201,13 @@ setFlags ext = do
 -- does not impose an arbitrary width limit on the output (in terms of number of columns). Instead,
 -- it respsects the 'pprCols' field in the structure returned by 'getSessionDynFlags', and thus
 -- gives a configurable width of output.
-doc :: GhcMonad m => SDoc -> m String
+doc :: GhcMonad m => O.SDoc -> m String
 doc sdoc = do
   flags <- getSessionDynFlags
   unqual <- getPrintUnqual
-  let style = mkUserStyle unqual AllTheWay
+  let style = O.mkUserStyle unqual O.AllTheWay
   let cols = pprCols flags
-      d = runSDoc sdoc (initSDocContext flags style)
+      d = O.runSDoc sdoc (O.initSDocContext flags style)
   return $ Pretty.fullRender Pretty.PageMode cols 1.5 string_txt "" d
 
   where
@@ -298,7 +303,7 @@ evalDeclarations decl = do
   names <- runDecls decl
   cleanUpDuplicateInstances
   flags <- getSessionDynFlags
-  return $ map (replace ":Interactive." "" . showPpr flags) names
+  return $ map (replace ":Interactive." "" . O.showPpr flags) names
 
 cleanUpDuplicateInstances :: GhcMonad m => m ()
 cleanUpDuplicateInstances = modifySession $ \hscEnv ->
@@ -326,7 +331,7 @@ getType :: GhcMonad m => String -> m String
 getType expr = do
   result <- exprType expr
   flags <- getSessionDynFlags
-  let typeStr = showSDocUnqual flags $ ppr result
+  let typeStr = O.showSDocUnqual flags $ O.ppr result
   return typeStr
 
 -- | A wrapper around @getInfo@. Return info about each name in the string.
@@ -363,16 +368,16 @@ getDescription str = do
 
 #if MIN_VERSION_ghc(7,8,0)
     printInfo (thing, fixity, classInstances, famInstances) =
-      pprTyThingInContextLoc thing $$
-      showFixity thing fixity $$
-      vcat (map GHC.pprInstance classInstances) $$
-      vcat (map GHC.pprFamInst famInstances)
+      pprTyThingInContextLoc thing O.$$
+      showFixity thing fixity O.$$
+      O.vcat (map GHC.pprInstance classInstances) O.$$
+      O.vcat (map GHC.pprFamInst famInstances)
 #else
     printInfo (thing, fixity, classInstances) =
-      pprTyThingInContextLoc False thing $$ showFixity thing fixity $$
-      vcat (map GHC.pprInstance classInstances)
+      pprTyThingInContextLoc False thing O.$$ showFixity thing fixity O.$$
+      O.vcat (map GHC.pprInstance classInstances)
 #endif
     showFixity thing fixity =
       if fixity == GHC.defaultFixity
-        then empty
-        else ppr fixity <+> pprInfixName (getName thing)
+        then O.empty
+        else O.ppr fixity O.<+> pprInfixName (getName thing)
diff --git a/src/IHaskell/Flags.hs b/src/IHaskell/Flags.hs
index 68cb5208..96b52c51 100644
--- a/src/IHaskell/Flags.hs
+++ b/src/IHaskell/Flags.hs
@@ -11,7 +11,13 @@ module IHaskell.Flags (
     help,
     ) where
 
-import           ClassyPrelude
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           System.Console.CmdArgs.Explicit
 import           System.Console.CmdArgs.Text
 import           Data.List (findIndex)
@@ -63,7 +69,7 @@ parseFlags flags =
     Nothing ->
       -- Treat no mode as 'console'.
       if "--help" `elem` flags
-        then Left $ pack (showText (Wrap 100) $ helpText [] HelpFormatAll ihaskellArgs)
+        then Left $ showText (Wrap 100) $ helpText [] HelpFormatAll ihaskellArgs
         else process ihaskellArgs flags
     Just 0 -> process ihaskellArgs flags
 
@@ -139,13 +145,13 @@ convert = mode "convert" (Args ConvertLhs []) description unnamedArg convertFlag
     consStyle style (Args mode prev) = Args mode (ConvertLhsStyle style : prev)
 
     storeFormat constructor str (Args mode prev) =
-      case toLower str of
+      case T.toLower (T.pack str) of
         "lhs"   -> Right $ Args mode $ constructor LhsMarkdown : prev
         "ipynb" -> Right $ Args mode $ constructor IpynbFile : prev
         _       -> Left $ "Unknown format requested: " ++ str
 
     storeLhs str previousArgs =
-      case toLower str of
+      case T.toLower (T.pack str) of
         "bird" -> success lhsStyleBird
         "tex"  -> success lhsStyleTex
         _      -> Left $ "Unknown lhs style: " ++ str
diff --git a/src/IHaskell/IPython.hs b/src/IHaskell/IPython.hs
index dbb17276..134409fd 100644
--- a/src/IHaskell/IPython.hs
+++ b/src/IHaskell/IPython.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NoImplicitPrelude, OverloadedStrings #-}
 {-# LANGUAGE DoAndIfThenElse #-}
 
 -- | Description : Shell scripting wrapper using @Shelly@ for the @notebook@, and
@@ -15,18 +14,21 @@ module IHaskell.IPython (
     defaultKernelSpecOptions,
     ) where
 
-import           ClassyPrelude
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Control.Concurrent (threadDelay)
-import           Prelude (read, reads, init)
-import           Shelly hiding (find, trace, path, (</>))
 import           System.Argv0
 import           System.Directory
+import qualified Shelly as SH
 import qualified Filesystem.Path.CurrentOS as FS
+import qualified System.IO as IO
 import           Data.List.Utils (split)
 import           Data.String.Utils (rstrip, endswith, strip, replace)
-import           Text.Printf
-import qualified Data.Text as T
-import           Data.Maybe (fromJust)
 import           System.Exit (exitFailure)
 import           Data.Aeson (toJSON)
 import           Data.Aeson.Encode (encodeToTextBuilder)
@@ -34,7 +36,6 @@ import           Data.Text.Lazy.Builder (toLazyText)
 
 import qualified System.IO.Strict as StrictIO
 import qualified Paths_ihaskell as Paths
-import qualified Codec.Archive.Tar as Tar
 
 import qualified GHC.Paths
 import           IHaskell.Types
@@ -64,72 +65,75 @@ kernelArgs = ["--kernel", kernelName]
 -- | Run the IPython command with any arguments. The kernel is set to IHaskell.
 ipython :: Bool         -- ^ Whether to suppress output.
         -> [Text]       -- ^ IPython command line arguments.
-        -> Sh String    -- ^ IPython output.
+        -> SH.Sh String    -- ^ IPython output.
 ipython suppress args = do
   liftIO $ installHandler keyboardSignal (CatchOnce $ return ()) Nothing
 
   -- We have this because using `run` does not let us use stdin.
-  runHandles "ipython" args handles doNothing
+  SH.runHandles "ipython" args handles doNothing
 
   where
-    handles = [InHandle Inherit, outHandle suppress, errorHandle suppress]
-    outHandle True = OutHandle CreatePipe
-    outHandle False = OutHandle Inherit
-    errorHandle True = ErrorHandle CreatePipe
-    errorHandle False = ErrorHandle Inherit
+    handles = [SH.InHandle SH.Inherit, outHandle suppress, errorHandle suppress]
+    outHandle True = SH.OutHandle SH.CreatePipe
+    outHandle False = SH.OutHandle SH.Inherit
+    errorHandle True = SH.ErrorHandle SH.CreatePipe
+    errorHandle False = SH.ErrorHandle SH.Inherit
     doNothing _ stdout _ = if suppress
                              then liftIO $ StrictIO.hGetContents stdout
                              else return ""
 
 -- | Run while suppressing all output.
-quietRun path args = runHandles path args handles nothing
+quietRun path args = SH.runHandles path args handles nothing
   where
-    handles = [InHandle Inherit, OutHandle CreatePipe, ErrorHandle CreatePipe]
+    handles = [SH.InHandle SH.Inherit, SH.OutHandle SH.CreatePipe, SH.ErrorHandle SH.CreatePipe]
     nothing _ _ _ = return ()
 
+fp :: FS.FilePath -> FilePath
+fp = T.unpack . SH.toTextIgnore
+
 -- | Create the directory and return it.
-ensure :: Sh FilePath -> Sh FilePath
+ensure :: SH.Sh FS.FilePath -> SH.Sh FS.FilePath
 ensure getDir = do
   dir <- getDir
-  mkdir_p dir
+  SH.mkdir_p dir
   return dir
 
 -- | Return the data directory for IHaskell.
-ihaskellDir :: Sh FilePath
+ihaskellDir :: SH.Sh FilePath
 ihaskellDir = do
-  home <- maybe (error "$HOME not defined.") fromText <$> get_env "HOME"
-  ensure $ return (home </> ".ihaskell")
+  home <- maybe (error "$HOME not defined.") FS.fromText <$> SH.get_env "HOME"
+  fp <$> ensure (return (home SH.</> ".ihaskell"))
 
-ipythonDir :: Sh FilePath
-ipythonDir = ensure $ (</> "ipython") <$> ihaskellDir
+ipythonDir :: SH.Sh FS.FilePath
+ipythonDir = ensure $ (SH.</> "ipython") <$> ihaskellDir
 
-notebookDir :: Sh FilePath
-notebookDir = ensure $ (</> "notebooks") <$> ihaskellDir
+notebookDir :: SH.Sh FS.FilePath
+notebookDir = ensure $ (SH.</> "notebooks") <$> ihaskellDir
 
 getIHaskellDir :: IO String
-getIHaskellDir = shelly $ fpToString <$> ihaskellDir
+getIHaskellDir = SH.shelly ihaskellDir
 
 defaultConfFile :: IO (Maybe String)
-defaultConfFile = shelly $ do
-  filename <- (</> "rc.hs") <$> ihaskellDir
-  exists <- test_f filename
+defaultConfFile = fmap (fmap fp) . SH.shelly $ do
+  filename <- (SH.</> "rc.hs") <$> ihaskellDir
+  exists <- SH.test_f filename
   return $ if exists
-             then Just $ fpToString filename
+             then Just filename
              else Nothing
 
 replaceIPythonKernelspec :: KernelSpecOptions -> IO ()
-replaceIPythonKernelspec kernelSpecOpts = shelly $ do
+replaceIPythonKernelspec kernelSpecOpts = SH.shelly $ do
   verifyIPythonVersion
   installKernelspec True kernelSpecOpts
 
 -- | Verify that a proper version of IPython is installed and accessible.
-verifyIPythonVersion :: Sh ()
+verifyIPythonVersion :: SH.Sh ()
 verifyIPythonVersion = do
-  pathMay <- which "ipython"
+  pathMay <- SH.which "ipython"
   case pathMay of
     Nothing -> badIPython "No IPython detected -- install IPython 3.0+ before using IHaskell."
     Just path -> do
-      output <- unpack <$> silently (run path ["--version"])
+      output <- T.unpack <$> SH.silently (SH.run path ["--version"])
       case parseVersion output of
         Just (3:_) -> return ()
         Just (2:_) -> oldIPython
@@ -138,15 +142,15 @@ verifyIPythonVersion = do
         _          -> badIPython "Detected IPython, but could not parse version number."
 
   where
-    badIPython :: Text -> Sh ()
+    badIPython :: Text -> SH.Sh ()
     badIPython message = liftIO $ do
-      hPutStrLn stderr message
+      IO.hPutStrLn IO.stderr (T.unpack message)
       exitFailure
     oldIPython = badIPython "Detected old version of IPython. IHaskell requires 3.0.0 or up."
 
 -- | Install an IHaskell kernelspec into the right location. The right location is determined by
 -- using `ipython kernelspec install --user`.
-installKernelspec :: Bool -> KernelSpecOptions -> Sh ()
+installKernelspec :: Bool -> KernelSpecOptions -> SH.Sh ()
 installKernelspec replace opts = void $ do
   ihaskellPath <- getIHaskellPath
   confFile <- liftIO $ kernelSpecConfFile opts
@@ -167,63 +171,57 @@ installKernelspec replace opts = void $ do
 
   -- Create a temporary directory. Use this temporary directory to make a kernelspec directory; then,
   -- shell out to IPython to install this kernelspec directory.
-  withTmpDir $ \tmp -> do
-    let kernelDir = tmp </> kernelName
-    let filename = kernelDir </> "kernel.json"
+  SH.withTmpDir $ \tmp -> do
+    let kernelDir = tmp SH.</> kernelName
+    let filename = kernelDir SH.</> "kernel.json"
 
-    mkdir_p kernelDir
-    writefile filename $ toStrict $ toLazyText $ encodeToTextBuilder $ toJSON kernelSpec
+    SH.mkdir_p kernelDir
+    SH.writefile filename $ LT.toStrict $ toLazyText $ encodeToTextBuilder $ toJSON kernelSpec
     let files = ["kernel.js", "logo-64x64.png"]
     forM_ files $ \file -> do
       src <- liftIO $ Paths.getDataFileName $ "html/" ++ file
-      cp (fpFromString src) (tmp </> kernelName </> fpFromString file)
+      SH.cp (FS.fromText $ T.pack src) (tmp SH.</> kernelName SH.</> file)
 
-    Just ipython <- which "ipython"
+    Just ipython <- SH.which "ipython"
     let replaceFlag = ["--replace" | replace]
-        cmd = ["kernelspec", "install", "--user", fpToText kernelDir] ++ replaceFlag
-    silently $ run ipython cmd
+        cmd = ["kernelspec", "install", "--user", kernelDir] ++ replaceFlag
+    SH.silently $ SH.run ipython (map SH.toTextIgnore cmd)
 
-kernelSpecCreated :: Sh Bool
+kernelSpecCreated :: SH.Sh Bool
 kernelSpecCreated = do
-  Just ipython <- which "ipython"
-  out <- silently $ run ipython ["kernelspec", "list"]
-  let kernelspecs = map T.strip $ lines out
+  Just ipython <- SH.which "ipython"
+  out <- SH.silently $ SH.run ipython ["kernelspec", "list"]
+  let kernelspecs = map T.strip $ T.lines out
   return $ kernelName `elem` kernelspecs
 
 -- | Replace "~" with $HOME if $HOME is defined. Otherwise, do nothing.
 subHome :: String -> IO String
-subHome path = shelly $ do
-  home <- unpack <$> fromMaybe "~" <$> get_env "HOME"
+subHome path = SH.shelly $ do
+  home <- T.unpack <$> fromMaybe "~" <$> SH.get_env "HOME"
   return $ replace "~" home path
 
 -- | Get the path to an executable. If it doensn't exist, fail with an error message complaining
 -- about it.
-path :: Text -> Sh FilePath
+path :: Text -> SH.Sh FS.FilePath
 path exe = do
-  path <- which $ fromText exe
+  path <- SH.which $ FS.fromText exe
   case path of
     Nothing -> do
-      putStrLn $ "Could not find `" ++ exe ++ "` executable."
-      fail $ "`" ++ unpack exe ++ "` not on $PATH."
+      liftIO $ putStrLn $ "Could not find `" ++ T.unpack exe ++ "` executable."
+      fail $ "`" ++ T.unpack exe ++ "` not on $PATH."
     Just exePath -> return exePath
 
 -- | Parse an IPython version string into a list of integers.
 parseVersion :: String -> Maybe [Int]
 parseVersion versionStr =
-  let versions = map read' $ split "." versionStr
+  let versions = map readMay $ split "." versionStr
       parsed = all isJust versions
   in if parsed
        then Just $ map fromJust versions
        else Nothing
-  where
-    read' :: String -> Maybe Int
-    read' x =
-      case reads x of
-        [(n, _)] -> Just n
-        _        -> Nothing
 
 -- | Get the absolute path to this IHaskell executable.
-getIHaskellPath :: Sh String
+getIHaskellPath :: SH.Sh String
 getIHaskellPath = do
   --  Get the absolute filepath to the argument.
   f <- liftIO getArgv0
@@ -236,17 +234,17 @@ getIHaskellPath = do
     -- the shell. If it's just 'IHaskell', use the $PATH variable to find where IHaskell lives.
     if FS.filename f == f
       then do
-        ihaskellPath <- which "ihaskell"
+        ihaskellPath <- SH.which "ihaskell"
         case ihaskellPath of
           Nothing   -> error "ihaskell not on $PATH and not referenced relative to directory."
           Just path -> return $ FS.encodeString path
       else do
         -- If it's actually a relative path, make it absolute.
         cd <- liftIO getCurrentDirectory
-        return $ FS.encodeString $ FS.decodeString cd FS.</> f
+        return $ FS.encodeString $ FS.decodeString cd SH.</> f
 
 getSandboxPackageConf :: IO (Maybe String)
-getSandboxPackageConf = shelly $ do
+getSandboxPackageConf = SH.shelly $ do
   myPath <- getIHaskellPath
   let sandboxName = ".cabal-sandbox"
   if not $ sandboxName `isInfixOf` myPath
@@ -254,8 +252,8 @@ getSandboxPackageConf = shelly $ do
     else do
       let pieces = split "/" myPath
           sandboxDir = intercalate "/" $ takeWhile (/= sandboxName) pieces ++ [sandboxName]
-      subdirs <- ls $ fpFromString sandboxDir
-      let confdirs = filter (endswith "packages.conf.d") $ map fpToString subdirs
+      subdirs <- map fp <$> SH.ls (FS.fromText $ T.pack sandboxDir)
+      let confdirs = filter (endswith ("packages.conf.d" :: String)) subdirs
       case confdirs of
         [] -> return Nothing
         dir:_ ->
diff --git a/src/IHaskell/IPython/Stdin.hs b/src/IHaskell/IPython/Stdin.hs
index ac9137ca..da4757a3 100644
--- a/src/IHaskell/IPython/Stdin.hs
+++ b/src/IHaskell/IPython/Stdin.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE OverloadedStrings, DoAndIfThenElse #-}
+{-# LANGUAGE NoImplicitPrelude, OverloadedStrings, DoAndIfThenElse #-}
 
 -- | This module provides a way in which the Haskell standard input may be forwarded to the IPython
 -- frontend and thus allows the notebook to use the standard input.
@@ -12,6 +12,7 @@
 -- communication. For this, use @recordKernelProfile@ once the profile is known. Both this and
 -- @recordParentHeader@ take a directory name where they can store this data.
 --
+--
 -- Finally, the module must know what @execute_request@ message is currently being replied to (which
 -- will request the input). Thus, every time the language kernel receives an @execute_request@
 -- message, it should inform this module via @recordParentHeader@, so that the module may generate
@@ -24,13 +25,19 @@
 -- the host code.
 module IHaskell.IPython.Stdin (fixStdin, recordParentHeader, recordKernelProfile) where
 
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import           Control.Concurrent
 import           Control.Applicative ((<$>))
 import           Control.Concurrent.Chan
 import           Control.Monad
 import           GHC.IO.Handle
 import           GHC.IO.Handle.Types
-import           System.IO
 import           System.Posix.IO
 import           System.IO.Unsafe
 import qualified Data.Map as Map
@@ -48,7 +55,7 @@ stdinInterface = unsafePerformIO newEmptyMVar
 fixStdin :: String -> IO ()
 fixStdin dir = do
   -- Initialize the stdin interface.
-  profile <- read <$> readFile (dir ++ "/.kernel-profile")
+  profile <- fromJust . readMay <$> readFile (dir ++ "/.kernel-profile")
   interface <- serveStdin profile
   putMVar stdinInterface interface
   void $ forkIO $ stdinOnce dir
@@ -87,7 +94,7 @@ getInputLine dir = do
 
   -- Send a request for input.
   uuid <- UUID.random
-  parentHeader <- read <$> readFile (dir ++ "/.last-req-header")
+  parentHeader <- fromJust . readMay <$> readFile (dir ++ "/.last-req-header")
   let header = MessageHeader
         { username = username parentHeader
         , identifiers = identifiers parentHeader
diff --git a/src/IHaskell/Types.hs b/src/IHaskell/Types.hs
index ce8340bc..63a1e208 100644
--- a/src/IHaskell/Types.hs
+++ b/src/IHaskell/Types.hs
@@ -30,11 +30,16 @@ module IHaskell.Types (
     KernelSpec(..),
     ) where
 
-import           ClassyPrelude
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
+
 import qualified Data.ByteString.Char8 as Char
 import           Data.Serialize
 import           GHC.Generics
-import           Data.Map (Map, empty)
 import           Data.Aeson (Value)
 
 import           IHaskell.IPython.Kernel
@@ -103,9 +108,6 @@ instance Monoid Display where
   a `mappend` ManyDisplay b = ManyDisplay (a : b)
   a `mappend` b = ManyDisplay [a, b]
 
-instance Semigroup Display where
-  a <> b = a `mappend` b
-
 -- | All state stored in the kernel between executions.
 data KernelState =
        KernelState
@@ -128,7 +130,7 @@ defaultKernelState = KernelState
   , useShowErrors = False
   , useShowTypes = False
   , usePager = True
-  , openComms = empty
+  , openComms = mempty
   , kernelDebug = False
   }
 
@@ -177,4 +179,4 @@ data EvaluationResult =
                                                       -- pager.
                           , startComms :: [CommInfo]  -- ^ Comms to start.
                           }
-  deriving Show
\ No newline at end of file
+  deriving Show
diff --git a/src/IHaskellPrelude.hs b/src/IHaskellPrelude.hs
new file mode 100644
index 00000000..79e1fffd
--- /dev/null
+++ b/src/IHaskellPrelude.hs
@@ -0,0 +1,138 @@
+module IHaskellPrelude (
+  module IHaskellPrelude,
+  module X,
+
+  -- Select reexports
+  Data.Typeable.Proxy,
+  Data.Typeable.Typeable,
+  Data.Typeable.cast,
+
+  GHC.Exts.IsString,
+  GHC.Exts.IsList,
+
+  System.IO.hPutStrLn,
+  System.IO.hPutStr,
+  System.IO.hPutChar,
+  System.IO.hPrint,
+  System.IO.stdout,
+  System.IO.stderr,
+  System.IO.stdin,
+  System.IO.getChar,
+  System.IO.getLine,
+  System.IO.writeFile,
+  System.IO.Handle,
+
+  System.IO.Strict.readFile,
+  System.IO.Strict.getContents,
+  System.IO.Strict.hGetContents,
+
+  Control.Exception.catch,
+  Control.Exception.SomeException,
+
+  Control.Applicative.Applicative(..),
+  Control.Applicative.ZipList(..),
+  (Control.Applicative.<$>),
+
+  Control.Concurrent.MVar.MVar,
+  Control.Concurrent.MVar.newMVar,
+  Control.Concurrent.MVar.newEmptyMVar,
+  Control.Concurrent.MVar.isEmptyMVar,
+  Control.Concurrent.MVar.readMVar,
+  Control.Concurrent.MVar.takeMVar,
+  Control.Concurrent.MVar.putMVar,
+  Control.Concurrent.MVar.modifyMVar,
+  Control.Concurrent.MVar.modifyMVar_,
+
+  Data.IORef.IORef,
+  Data.IORef.readIORef,
+  Data.IORef.writeIORef,
+  Data.IORef.modifyIORef',
+  Data.IORef.newIORef,
+
+  
+
+  -- Miscellaneous names
+  Data.Map.Map,
+  GHC.IO.FilePath,
+  Data.Text.Text,
+  Data.ByteString.ByteString,
+  Text.Printf.printf,
+  Data.Function.on,
+  ) where
+
+import           Prelude
+
+import           Data.Monoid            as X
+import           Data.Tuple             as X
+import           Control.Monad          as X
+import           Data.Maybe             as X
+import           Data.Either            as X
+import           Control.Monad.IO.Class as X
+import           Data.Ord               as X
+import           GHC.Show               as X
+import           GHC.Enum               as X
+import           GHC.Num                as X
+import           GHC.Real               as X
+import           GHC.Base               as X hiding (Any)
+import           Data.List              as X hiding (head, last, tail, init, transpose, subsequences, permutations,
+                                        foldl, foldl1, maximum, minimum, scanl, scanl1, scanr, scanr1, span, break,
+                                        mapAccumL, mapAccumR, dropWhileEnd, (!!), elemIndices,
+                                        elemIndex, findIndex, findIndices, zip5, zip6, zip7, zipWith5,
+                                        zipWith6, zipWith7, unzip5, unzip6, unzip6, delete, union, lookup,
+                                        intersect, insert, deleteBy, deleteFirstBy, unionBy,
+                                        intersectBy, group, groupBy, insertBy, maximumBy, minimumBy,
+                                        genericLength, genericDrop, genericTake, genericSplitAt,
+                                        genericIndex, genericReplicate, inits, tails)
+
+import qualified Control.Applicative
+import qualified Data.Typeable
+import qualified Data.IORef
+import qualified Data.Map
+import qualified Data.Text
+import qualified Data.Text.Lazy
+import qualified Data.ByteString
+import qualified Data.ByteString.Lazy
+import qualified Data.Function
+import qualified GHC.Exts
+import qualified System.IO
+import qualified System.IO.Strict
+import qualified GHC.IO
+import qualified Text.Printf
+import qualified Control.Exception
+import qualified Control.Concurrent.MVar
+
+import qualified Data.List
+import qualified Prelude as P
+
+type LByteString = Data.ByteString.Lazy.ByteString
+type LText = Data.Text.Lazy.Text
+
+(headMay, tailMay, lastMay, initMay, maximumMay, minimumMay) =
+  (wrapEmpty head, wrapEmpty tail, wrapEmpty last, wrapEmpty init, wrapEmpty maximum, wrapEmpty minimum)
+  where
+    wrapEmpty :: ([a] -> b) -> [a] -> Maybe b
+    wrapEmpty _ [] = Nothing
+    wrapEmpty f xs = Just (f xs)
+
+maximumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a
+maximumByMay _ [] = Nothing
+maximumByMay f xs = Just (Data.List.maximumBy f xs)
+
+minimumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a
+minimumByMay _ [] = Nothing
+minimumByMay f xs = Just (Data.List.minimumBy f xs)
+
+readMay :: Read a => String -> Maybe a
+readMay = fmap fst . headMay  . reads
+
+putStrLn :: (MonadIO m) => String -> m ()
+putStrLn = liftIO . P.putStrLn
+
+putStr :: (MonadIO m) => String -> m ()
+putStr = liftIO . P.putStr
+
+putChar:: MonadIO m => Char -> m ()
+putChar = liftIO . P.putChar
+
+print :: (MonadIO m, Show a) => a -> m ()
+print = liftIO . P.print
diff --git a/src/Main.hs b/src/Main.hs
index c7f61df3..db69043f 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -4,22 +4,24 @@
 --                 Chans to communicate with the ZeroMQ sockets.
 module Main (main) where
 
--- Prelude imports.
-import           ClassyPrelude hiding (last, liftIO, readChan, writeChan)
-import           Prelude (last, read)
+import           IHaskellPrelude
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.ByteString.Char8 as CBS
 
 -- Standard library imports.
 import           Control.Concurrent (threadDelay)
 import           Control.Concurrent.Chan
 import           Data.Aeson
-import           Data.Text (strip)
 import           System.Directory
 import           System.Exit (exitSuccess)
-import           Text.Printf
+import           System.Environment (getArgs)
 import           System.Posix.Signals
 import qualified Data.Map as Map
 import           Data.String.Here (hereFile)
-import qualified Data.Text as T
+import qualified Data.Text.Encoding as E
 
 -- IHaskell imports.
 import           IHaskell.Convert (convert)
@@ -33,7 +35,6 @@ import           IHaskell.IPython
 import           IHaskell.Types
 import           IHaskell.IPython.ZeroMQ
 import           IHaskell.IPython.Types
-import qualified Data.ByteString.Char8 as Chars
 import qualified IHaskell.IPython.Message.UUID as UUID
 import qualified IHaskell.IPython.Stdin as Stdin
 
@@ -42,7 +43,7 @@ import           GHC hiding (extensions, language)
 
 -- | Compute the GHC API version number using the dist/build/autogen/cabal_macros.h
 ghcVersionInts :: [Int]
-ghcVersionInts = map read . words . map dotToSpace $ VERSION_ghc
+ghcVersionInts = map (fromJust . readMay) . words . map dotToSpace $ VERSION_ghc
   where
     dotToSpace '.' = ' '
     dotToSpace x = x
@@ -52,18 +53,18 @@ ihaskellCSS = [hereFile|html/custom.css|]
 
 consoleBanner :: Text
 consoleBanner =
-  "Welcome to IHaskell! Run `IHaskell --help` for more information.\n" ++
+  "Welcome to IHaskell! Run `IHaskell --help` for more information.\n" <>
   "Enter `:help` to learn more about IHaskell built-ins."
 
 main :: IO ()
 main = do
-  args <- parseFlags <$> map unpack <$> getArgs
+  args <- parseFlags <$> getArgs
   case args of
     Left errorMessage -> hPutStrLn stderr errorMessage
     Right args        -> ihaskell args
 
 ihaskell :: Args -> IO ()
-ihaskell (Args (ShowHelp help) _) = putStrLn $ pack help
+ihaskell (Args (ShowHelp help) _) = putStrLn help
 ihaskell (Args ConvertLhs args) = showingHelp ConvertLhs args $ convert args
 ihaskell (Args InstallKernelSpec args) = showingHelp InstallKernelSpec args $ do
   let kernelSpecOpts = parseKernelArgs args
@@ -76,7 +77,7 @@ showingHelp :: IHaskellMode -> [Argument] -> IO () -> IO ()
 showingHelp mode flags act =
   case find (== Help) flags of
     Just _ ->
-      putStrLn $ pack $ help mode
+      putStrLn $ help mode
     Nothing ->
       act
 
@@ -101,7 +102,7 @@ runKernel kernelOpts profileSrc = do
       libdir = kernelSpecGhcLibdir kernelOpts
 
   -- Parse the profile file.
-  Just profile <- liftM decode . readFile . fpFromString $ profileSrc
+  Just profile <- liftM decode $ LBS.readFile profileSrc
 
   -- Necessary for `getLine` and their ilk to work.
   dir <- getIHaskellDir
@@ -131,7 +132,7 @@ runKernel kernelOpts profileSrc = do
 
     confFile <- liftIO $ kernelSpecConfFile kernelOpts
     case confFile of
-      Just filename -> liftIO (readFile $ fpFromString filename) >>= evaluator
+      Just filename -> liftIO (readFile filename) >>= evaluator
       Nothing       -> return ()
 
     forever $ do
@@ -247,12 +248,14 @@ replyTo interface req@ExecuteRequest { getCode = code } replyHeader state = do
         header <- dupHeader replyHeader DisplayDataMessage
         send $ PublishDisplayData header "haskell" $ map (convertSvgToHtml . prependCss) outs
 
-      convertSvgToHtml (DisplayData MimeSvg svg) = html $ makeSvgImg $ base64 $ encodeUtf8 svg
+      convertSvgToHtml (DisplayData MimeSvg svg) = html $ makeSvgImg $ base64 $ E.encodeUtf8 svg
       convertSvgToHtml x = x
-      makeSvgImg base64data = unpack $ "<img src=\"data:image/svg+xml;base64," ++ base64data ++ "\"/>"
+
+      makeSvgImg :: Base64 -> String
+      makeSvgImg base64data = T.unpack $ "<img src=\"data:image/svg+xml;base64," <> base64data <> "\"/>"
 
       prependCss (DisplayData MimeHtml html) =
-        DisplayData MimeHtml $concat ["<style>", pack ihaskellCSS, "</style>", html]
+        DisplayData MimeHtml $ mconcat ["<style>", T.pack ihaskellCSS, "</style>", html]
       prependCss x = x
 
       startComm :: CommInfo -> IO ()
@@ -304,10 +307,10 @@ replyTo interface req@ExecuteRequest { getCode = code } replyHeader state = do
   let execCount = getExecutionCounter state
   -- Let all frontends know the execution count and code that's about to run
   inputHeader <- liftIO $ dupHeader replyHeader InputMessage
-  send $ PublishInput inputHeader (unpack code) execCount
+  send $ PublishInput inputHeader (T.unpack code) execCount
 
   -- Run code and publish to the frontend as we go.
-  updatedState <- evaluate state (unpack code) publish
+  updatedState <- evaluate state (T.unpack code) publish
 
   -- Notify the frontend that we're done computing.
   idleHeader <- liftIO $ dupHeader replyHeader StatusMessage
@@ -329,15 +332,15 @@ replyTo interface req@ExecuteRequest { getCode = code } replyHeader state = do
 replyTo _ req@CompleteRequest{} replyHeader state = do
   let code = getCode req
       pos = getCursorPos req
-  (matchedText, completions) <- complete (unpack code) pos
+  (matchedText, completions) <- complete (T.unpack code) pos
 
   let start = pos - length matchedText
       end = pos
-      reply = CompleteReply replyHeader (map pack completions) start end Map.empty True
+      reply = CompleteReply replyHeader (map T.pack completions) start end Map.empty True
   return (state, reply)
 
 replyTo _ req@InspectRequest{} replyHeader state = do
-  result <- inspect (unpack $ inspectCode req) (inspectCursorPos req)
+  result <- inspect (T.unpack $ inspectCode req) (inspectCursorPos req)
   let reply =
         case result of
           Just (Display datas) -> InspectReply
@@ -365,7 +368,7 @@ handleComm replier kernelState req replyHeader = do
       communicate value = do
         head <- dupHeader replyHeader CommDataMessage
         replier $ CommData head uuid value
-  case lookup uuid widgets of
+  case Map.lookup uuid widgets of
     Nothing -> fail $ "no widget with uuid " ++ show uuid
     Just (Widget widget) ->
       case msgType $ header req of