diff --git a/CHANGELOG.md b/CHANGELOG.md
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+# Changelog
+
+## 0.1.0.0 (2020-02-29)
+Inital version
+
+### Additions
+- `MonadChoice`
+  - Created `MonadChoice` typeclass to represent that allow choices to be made by some arbitrary entity.
+  - Added function `chooseM`.
+  - Added instances for the `ChoiceT` both covariant and invariant.
+  - Added instance for `MonadRandom` instances by using the `uniform` function.
+  - Added various passthrough instances
+    - `MaybeT`
+    - `ExceptT`
+    - `IdentityT`
+    - `StateT` either lazy or strict
+    - `ReaderT`
+    - `WriterT` either constant space, lazy, or strict
+    - `AccumT`
+    - `ContT`
+    - `RWST` either constant space, lazy, strict
+    - `SelectT`
+- `ChoiceT`
+  - Added two different versions of `ChoiceT`, one a covariant functor, the other an invariant functor on the category of monads.
+  - Shared additions:
+    - Function `runChoiceT`
+    - Instances for `Functor`, `Applicative`, `Monad`, `MonadTrans`, and `MonadChoice`
+    - Various passthrough instances
+      - `MonadReader`
+      - `MonadState`
+      - `MonadWriter`
+      - `MonadRWS`
+      - `MonadIO`
+  - `Covariant.ChoiceT`
+    - Added functions `mapChoiceT` and `runBacktrackableChoiceT`.
+  - `Invariant.ChoiceT`
+    - Exposed constructor `ChoiceT`.
+    - Added function `invmapChoiceT`.
+    - Added various passthrough instances.
+      - `Contravariant`
+      - `Invariant`
+      - `Alternative`
+      - `MonadPlus`
+      - `MonadError`
+- `Choice`
+  - Added two different versions of `Choice` which of type aliases for each `ChoiceT` over the `Identity` monad.
+  - Added function `runChoice` for each version.
+  - For `Covariant.Choice` added functions `runChoiceM` and `runBacktrackableChoiceT`.
diff --git a/LICENSE b/LICENSE
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+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
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+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
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+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
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+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
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+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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+
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,17 @@
+# The `monad-choice` package
+
+This package provides a multipurpose monad transformer (and associated monad and class), to represent the idea of a result depending on the outcomes of a series of choices.
+
+## Example
+
+The following is a simple use of `MonadChoice` for creating the name of a berry.
+
+    {-# Language FlexibleContexts #-}
+
+    berry :: MonadChoice NonEmpty m => m String
+    berry = do
+      berryColor  <- choose $ "red"   :| ["blue", "orange", "yellow", "black"]
+      berryFlavor <- choose $ "sweet" :| ["sour", "bitter"]
+      (++ "berry") <$> choose ( berryColor :| [berryFlavor, berryColor ++ "-" ++ berryFlavor] )
+
+This can be used with `MonadRandom` to create a random berry, used with `Gen` to create berries for unit tests, or with user input as the structure for a menu where the user selects a berry.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/monad-choice.cabal b/monad-choice.cabal
new file mode 100644
--- /dev/null
+++ b/monad-choice.cabal
@@ -0,0 +1,47 @@
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.2.
+--
+-- see: https://github.com/sol/hpack
+--
+-- hash: 6b28c8a7bf1da981f4efd400c5e91cb2a160d9cc56dadee09cad68c0d7d40c6c
+
+name:           monad-choice
+version:        0.1.0.0
+synopsis:       Monad, monad transformer, and typeclass representing choices.
+description:    The Monad Choice library contains monads, monad transformers, and a typeclass representing a sequence of choices of objects of arbitrary types where future choices can depend on previous ones.
+category:       Control
+homepage:       https://gitlab.com/e-neighborhood-watch/monad-choice#readme
+author:         Eamon Olive, Louis Hyde
+maintainer:     ejolive97@gmail.com
+copyright:      2020 Eamon Olive, Louis Hyde
+license:        AGPL-3
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    CHANGELOG.md
+
+source-repository head
+  type: git
+  location: https://gitlab.com/e-neighborhood-watch/monad-choice.git
+
+library
+  exposed-modules:
+      Control.Monad.Choice.Covariant
+      Control.Monad.Choice.Invariant
+      Control.Monad.Class.Choice
+      Control.Monad.Trans.Choice.Covariant
+      Control.Monad.Trans.Choice.Invariant
+  other-modules:
+      Paths_monad_choice
+  hs-source-dirs:
+      src
+  ghc-options: -Weverything -Wno-implicit-prelude -Wno-safe
+  build-depends:
+      MonadRandom >=0.5 && <0.6
+    , base >=4.7 && <5
+    , invariant >=0.1.0 && <0.6
+    , mtl >=2.2 && <2.3
+    , transformers ==0.5.*
+  default-language: Haskell2010
diff --git a/src/Control/Monad/Choice/Covariant.hs b/src/Control/Monad/Choice/Covariant.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Monad/Choice/Covariant.hs
@@ -0,0 +1,44 @@
+{-# LANGUAGE RankNTypes #-}
+
+{-|
+Module     : Control.Monad.Choice.Covariant
+Copyright  : (c) Eamon Olive, 2020
+             (c) Louis Hyde,  2020
+License    : AGPL-3
+Maintainer : ejolive97@gmail.com
+Stability  : experimental
+
+-}
+module Control.Monad.Choice.Covariant
+  ( Choice
+  , runChoice
+  , runChoiceM
+  , runBacktrackableChoiceM
+  ) where
+
+-- Internal imports
+
+import Control.Monad.Trans.Choice.Covariant
+  ( ChoiceT
+  , mapChoiceT
+  , runBacktrackableChoiceT
+  , runChoiceT
+  )
+
+-- External imports
+
+import Control.Monad.Identity
+  ( Identity
+  , runIdentity
+  )
+
+type Choice f = ChoiceT f Identity
+
+runChoice :: (forall x. f x -> x) -> Choice f a -> a
+runChoice chooser = runIdentity . runChoiceT (pure . chooser)
+
+runChoiceM :: Monad m => (forall x. f x -> m x) -> Choice f a -> m a
+runChoiceM chooser = runChoiceT chooser . mapChoiceT (pure . runIdentity)
+
+runBacktrackableChoiceM :: Monad m => (forall x. f x -> m (Maybe x)) -> Choice f a -> m (Maybe a)
+runBacktrackableChoiceM chooser = runBacktrackableChoiceT chooser . mapChoiceT (pure . runIdentity)
diff --git a/src/Control/Monad/Choice/Invariant.hs b/src/Control/Monad/Choice/Invariant.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Monad/Choice/Invariant.hs
@@ -0,0 +1,38 @@
+{-# LANGUAGE RankNTypes #-}
+
+{-|
+Module     : Control.Monad.Choice.Invariant
+Copyright  : (c) Eamon Olive, 2020
+             (c) Louis Hyde,  2020
+License    : AGPL-3
+Maintainer : ejolive97@gmail.com
+Stability  : experimental
+
+-}
+module Control.Monad.Choice.Invariant
+  ( Choice
+  , runChoice
+  ) where
+
+-- Internal imports
+
+import Control.Monad.Trans.Choice.Invariant
+  ( ChoiceT
+  , runChoiceT
+  )
+
+-- External imports
+
+import Data.Functor.Identity
+  ( Identity
+    ( runIdentity
+    )
+  )
+
+type Choice f a = ChoiceT f Identity a
+
+runChoice ::
+  (forall x . f x -> x)
+    -> Choice f a
+      -> a
+runChoice chooser = runIdentity . runChoiceT (\options -> pure $ chooser options)
diff --git a/src/Control/Monad/Class/Choice.hs b/src/Control/Monad/Class/Choice.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Monad/Class/Choice.hs
@@ -0,0 +1,144 @@
+{-# Language MultiParamTypeClasses #-}
+{-# Language FlexibleInstances #-}
+
+{-|
+Module     : Control.Monad.Class.Choice
+Copyright  : (c) Eamon Olive, 2020
+             (c) Louis Hyde,  2020
+License    : AGPL-3
+Maintainer : ejolive97@gmail.com
+Stability  : experimental
+
+-}
+module Control.Monad.Class.Choice
+  ( MonadChoice (..)
+  , chooseM
+  )
+  where
+
+import Control.Monad
+  ( join
+  )
+import Control.Monad.Random.Class
+  ( MonadRandom
+  , uniform
+  )
+import Control.Monad.Trans
+  ( lift
+  )
+import Control.Monad.Trans.Accum
+  ( AccumT
+  )
+import Control.Monad.Trans.Cont
+  ( ContT
+  )
+import Control.Monad.Trans.Except
+  ( ExceptT
+  )
+import Control.Monad.Trans.Identity
+  ( IdentityT
+  )
+import Control.Monad.Trans.Maybe
+  ( MaybeT
+  )
+import Control.Monad.Trans.Reader
+  ( ReaderT
+  )
+import Control.Monad.Trans.RWS.CPS as RWS.CPS
+  ( RWST
+  )
+import Control.Monad.Trans.RWS.Lazy as RWS.Lazy
+  ( RWST
+  )
+import Control.Monad.Trans.RWS.Strict as RWS.Strict
+  ( RWST
+  )
+import Control.Monad.Trans.Select
+  ( SelectT
+  )
+import Control.Monad.Trans.State.Lazy as State.Lazy
+  ( StateT
+  )
+import Control.Monad.Trans.State.Strict as State.Strict
+  ( StateT
+  )
+import Control.Monad.Trans.Writer.CPS as Writer.CPS
+  ( WriterT
+  )
+import Control.Monad.Trans.Writer.Lazy as Writer.Lazy
+  ( WriterT
+  )
+import Control.Monad.Trans.Writer.Strict as Writer.Strict
+  ( WriterT
+  )
+
+-- | A monad with a series of dependent choices.
+-- It is usually desirable to have @f@ be a 'Foldable' so that a selection can be made from it.
+--
+-- As an example here is a simple berry name generator:
+--
+-- > berry :: MonadChoice NonEmpty m => m String
+-- > berry = do
+-- >   color  <- choose $ "red" :| ["blue", "pink", "cyan"]
+-- >   prefix <- choose $ "color" :| ["straw", "rasp", "cran"]
+-- >   return $ prefix ++ "berry"
+--
+-- Since this has a polymorphic type this could be used for a variety of purposes.
+class Monad m => MonadChoice f m where
+  -- | Makes a selection.
+  choose :: f a -> m a
+
+-- | Makes a selection where options are themselves selections.
+chooseM ::
+  ( MonadChoice f m
+  )
+    => f (m a) -> m a
+chooseM = join . choose
+
+instance (Foldable f, MonadRandom m) => MonadChoice f m where
+  choose = uniform
+
+instance MonadChoice f m => MonadChoice f (MaybeT m) where
+  choose = lift . choose 
+
+instance MonadChoice f m => MonadChoice f (ExceptT e m) where
+  choose = lift . choose 
+
+instance MonadChoice f m => MonadChoice f (IdentityT m) where
+  choose = lift . choose 
+
+instance MonadChoice f m => MonadChoice f (State.Lazy.StateT s m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (State.Strict.StateT s m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (ReaderT r m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (Writer.CPS.WriterT w m) where
+  choose = lift . choose
+
+instance (Monoid w, MonadChoice f m) => MonadChoice f (Writer.Lazy.WriterT w m) where
+  choose = lift . choose
+
+instance (Monoid w, MonadChoice f m) => MonadChoice f (Writer.Strict.WriterT w m) where
+  choose = lift . choose
+
+instance (Monoid w, MonadChoice f m) => MonadChoice f (AccumT w m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (ContT r m) where
+  choose = lift . choose
+
+instance (Monoid w, MonadChoice f m) => MonadChoice f (RWS.Lazy.RWST r w s m) where
+  choose = lift . choose
+
+instance (Monoid w, MonadChoice f m) => MonadChoice f (RWS.Strict.RWST r w s m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (RWS.CPS.RWST r w s m) where
+  choose = lift . choose
+
+instance MonadChoice f m => MonadChoice f (SelectT r m) where
+  choose = lift . choose
diff --git a/src/Control/Monad/Trans/Choice/Covariant.hs b/src/Control/Monad/Trans/Choice/Covariant.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Monad/Trans/Choice/Covariant.hs
@@ -0,0 +1,164 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE GADTs #-}
+
+{-|
+Module     : Control.Monad.Trans.Choice.Covariant
+Copyright  : (c) Eamon Olive, 2020
+             (c) Louis Hyde,  2020
+License    : AGPL-3
+Maintainer : ejolive97@gmail.com
+Stability  : experimental
+
+-}
+module Control.Monad.Trans.Choice.Covariant
+  ( ChoiceT ( )
+  , runChoiceT
+  , mapChoiceT
+  , runBacktrackableChoiceT
+  ) where
+
+-- Internal imports
+
+import Control.Monad.Class.Choice
+  ( MonadChoice (choose)
+  )
+
+-- External imports
+
+import Control.Arrow
+  ( second
+  )
+import Control.Monad
+  ( (>=>)
+  )
+import Control.Monad.IO.Class
+  ( MonadIO
+    ( liftIO
+    )
+  )
+import Control.Monad.Reader.Class
+  ( MonadReader
+    ( ask
+    , local
+    )
+  )
+import Control.Monad.RWS.Class
+  ( MonadRWS
+  )
+import Control.Monad.State.Class
+  ( MonadState
+    ( state
+    )
+  )
+import Control.Monad.Trans
+  ( MonadTrans
+    ( lift
+    )
+  )
+import Control.Monad.Writer.Class
+  ( MonadWriter
+    ( writer
+    , listen
+    , pass
+    )
+  )
+
+data ChoiceT f m a where
+  FixedT :: a -> ChoiceT f m a
+  LiftThenT :: m b -> (b -> ChoiceT f m a) -> ChoiceT f m a
+  ChooseThenT :: f b -> (b -> ChoiceT f m a) -> ChoiceT f m a
+
+instance Functor (ChoiceT f m) where
+  fmap f (FixedT value) = FixedT $ f value
+  fmap f (LiftThenT action next) = LiftThenT action $ fmap f . next
+  fmap f (ChooseThenT options next) = ChooseThenT options $ fmap f . next
+
+instance Applicative (ChoiceT f m) where
+  pure = FixedT -- === LiftThenT (pure value) $ FixedT
+
+  (FixedT f) <*> choice = fmap f choice
+  fChoice <*> (FixedT f) = fmap ($f) fChoice
+  -- Proof:
+  --
+  -- > LiftThenT action next = lift action >>= next
+  -- > 
+  -- > (a >>= b) >>= (<$> c) = (a >>= b) >>= (<$> c)
+  -- > (a >>= b) >>= (<$> c) = a >>= (\x -> (b x >>= (<$> c)))
+  -- > (a >>= b) <*> c = a >>= (\x -> (b x <*> c))
+  (LiftThenT   fAction  nextF) <*> dependentChoice = LiftThenT   fAction  $ (<*> dependentChoice) . nextF
+  (ChooseThenT fOptions nextF) <*> dependentChoice = ChooseThenT fOptions $ (<*> dependentChoice) . nextF
+
+instance Monad (ChoiceT f m) where
+  (FixedT value) >>= f = f value
+  (LiftThenT action next) >>= f = LiftThenT action $ next >=> f
+  (ChooseThenT options next) >>= f = ChooseThenT options $ next >=> f
+
+instance MonadChoice f (ChoiceT f m) where
+  choose options = ChooseThenT options pure
+
+instance MonadTrans (ChoiceT f) where
+  lift action = LiftThenT action pure
+
+instance MonadReader r m => MonadReader r (ChoiceT f m) where
+  ask = lift ask
+  local f = mapChoiceT (local f)
+
+instance MonadState s m => MonadState s (ChoiceT f m) where
+  state = lift . state
+
+instance MonadWriter w m => MonadWriter w (ChoiceT f m) where
+  writer = lift . writer
+  listen (FixedT value) = FixedT (value, mempty)
+  listen (LiftThenT action next) = LiftThenT (listen action) $ \(result, output) -> fmap (second $ mappend output) $ listen $ next result
+  listen (ChooseThenT options next) = ChooseThenT options $ listen . next
+  pass = go mempty
+    where
+      go :: w -> ChoiceT f m (a, w -> w) -> ChoiceT f m a
+      go acc (FixedT (value, f)) = writer (value, f acc)
+      go acc (LiftThenT action next) = LiftThenT (listen action) (\(a,w)-> go (acc <> w) $ next a)
+      go acc (ChooseThenT options next) = ChooseThenT options $ go acc . next
+
+instance MonadRWS r w s m => MonadRWS  r w s (ChoiceT f m)
+
+instance MonadIO m => MonadIO (ChoiceT f m) where
+  liftIO = lift . liftIO
+
+mapChoiceT :: (forall x. m x -> n x) -> ChoiceT f m a -> ChoiceT f n a
+mapChoiceT _ (FixedT value) = FixedT value
+mapChoiceT f (LiftThenT action next) = LiftThenT (f action) (mapChoiceT f . next)
+mapChoiceT f (ChooseThenT options next) = ChooseThenT options (mapChoiceT f . next)
+
+runChoiceT :: Monad m => (forall x. f x -> m x) -> ChoiceT f m a -> m a
+runChoiceT _ (FixedT value) = pure value
+runChoiceT chooser (LiftThenT action next) = action >>= (runChoiceT chooser . next)
+runChoiceT chooser (ChooseThenT options next) = chooser options >>= (runChoiceT chooser . next)
+
+-- | A variant of 'runChoiceT' that allows for the selection function to
+-- output 'Nothing' to represent the desire to potentially select a different
+-- option for the previous choice.
+runBacktrackableChoiceT ::
+  forall f m a. Monad m
+    =>
+      (forall x. f x -> m (Maybe x)) -- ^ The selection function.
+                                     -- If the result of the outputted computation is 'Nothing' then
+                                     -- 'runBacktrackableChoiceT' will backtrack to the previous choice.
+                                     -- Otherwise, the result is a 'Just' then it will proceed like 'runChoiceT'.
+        -> ChoiceT f m a             -- ^ The choice structure to run
+          -> m (Maybe a)             -- ^ The resulting computation. If the selection function backtracks on the
+                                     -- first choice the result of the computation will be 'Nothing'.
+runBacktrackableChoiceT _ (FixedT firstValue) = return $ Just firstValue
+runBacktrackableChoiceT chooser (LiftThenT action next) = action >>= runBacktrackableChoiceT chooser . next
+runBacktrackableChoiceT chooser (ChooseThenT options next) =
+  do
+    maybeChoice <- chooser options
+    case maybeChoice of
+      Nothing -> return Nothing
+      Just choice -> do
+        maybeResult <- runBacktrackableChoiceT chooser $ next choice
+        case maybeResult of
+          Nothing -> runBacktrackableChoiceT chooser $ ChooseThenT options next
+          Just result -> return $ Just result
diff --git a/src/Control/Monad/Trans/Choice/Invariant.hs b/src/Control/Monad/Trans/Choice/Invariant.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Monad/Trans/Choice/Invariant.hs
@@ -0,0 +1,185 @@
+{-# Language RankNTypes #-}
+{-# Language FlexibleInstances #-}
+{-# Language ScopedTypeVariables #-}
+{-# Language UndecidableInstances #-}
+{-# Language MultiParamTypeClasses #-}
+
+{-|
+Module     : Control.Monad.Trans.Choice.Invariant
+Copyright  : (c) Eamon Olive, 2020
+             (c) Louis Hyde,  2020
+License    : AGPL-3
+Maintainer : ejolive97@gmail.com
+Stability  : experimental
+
+-}
+module Control.Monad.Trans.Choice.Invariant
+  ( ChoiceT
+    ( ChoiceT
+    )
+  , runChoiceT
+  , invmapChoiceT
+  ) where
+
+-- Internal imports
+
+import Control.Monad.Class.Choice
+  ( MonadChoice
+  , choose
+  )
+
+-- External imports
+
+import Control.Applicative
+  ( Alternative
+    ( empty
+    , (<|>)
+    )
+  )
+import Control.Monad.Except
+  ( MonadError
+    ( throwError
+    , catchError
+    )
+  )
+import Control.Monad
+  ( MonadPlus
+  )
+import Control.Monad.IO.Class
+  ( MonadIO
+    ( liftIO
+    )
+  )
+import Control.Monad.Reader.Class
+  ( MonadReader
+    ( ask
+    , local
+    )
+  )
+import Control.Monad.State.Class
+  ( MonadState
+    ( get
+    , put
+    )
+  )
+import Control.Monad.Trans
+  ( MonadTrans
+  , lift
+  )
+import Control.Monad.Writer.Class
+  ( MonadWriter
+    ( listen
+    , pass
+    , tell
+    )
+  )
+import Data.Functor.Contravariant
+  ( Contravariant
+    ( contramap
+    )
+  )
+import Data.Functor.Invariant
+  ( Invariant
+    ( invmap
+    )
+  )
+
+-- | The choice monad transformer
+-- It takes a monad and enriches it with choice.
+newtype ChoiceT f m a = ChoiceT
+  { _runChoiceT :: (forall x . f x -> m x) -> m a
+  -- ^ Should not be used externally.
+  -- runChoiceT has the proper argument order.
+  }
+
+-- | Transforms the computation inside the 'ChoiceT'.
+-- This function differs from other map functions over the monads in monad transformers in that it requires an additional function of type @forall x . n x -> m x@.
+-- This is because 'ChoiceT' is not a covariant functor over the category of monads, but rather an invariant functor.
+-- 
+invmapChoiceT ::
+  (forall x . n x -> m x)
+    -> (m a -> n b)
+      -> ChoiceT f m a
+        -> ChoiceT f n b
+invmapChoiceT f g m1 = ChoiceT (\ chooser -> g $ runChoiceT (\ options -> f $ chooser options) m1)
+
+-- | Use a chooser to perform all the selections of a 'ChoiceT'.
+-- This uses a sensible argument order unlike many of the other monad transformers.
+runChoiceT ::
+  (forall x . f x -> m x)
+  -- ^ A chooser which can perform selections over @f@s containing arbitrary @x@s.
+  -- This will be used to determine the result of each selection.
+  -- 
+  -- This type proves the theorem :
+  --
+  -- > chooser (fmap f x) = fmap f (chooser x)
+    -> ChoiceT f m a
+    -- ^ A monad transformed by 'ChoiceT' to contain choices
+      -> m a
+      -- ^ The initial monad with the 'ChoiceT' removed and thus the choices resolved.
+runChoiceT chooser m1 = _runChoiceT m1 chooser
+
+-- | This acts as an map but does not go as "deep" as 'fmap'.
+--
+-- prop> lowMap f . lift = lift . f
+--
+-- prop> lowMap id = id
+--
+lowMap ::
+  (m a -> m b)
+    -> (ChoiceT f m a -> ChoiceT f m b)
+lowMap f m = ChoiceT (\ chooser -> f $ runChoiceT chooser m)
+    
+
+instance Functor m => Functor (ChoiceT f m) where
+  fmap f (ChoiceT deChooser) = ChoiceT (\ chooser -> fmap f $ deChooser chooser)
+
+instance Contravariant m => Contravariant (ChoiceT f m) where
+  contramap f (ChoiceT deChooser) = ChoiceT (\ chooser -> contramap f $ deChooser chooser)
+
+instance Invariant m => Invariant (ChoiceT f m) where
+  invmap f1 f2 (ChoiceT deChooser) = ChoiceT (\ chooser -> invmap f1 f2 $ deChooser chooser)
+
+instance Applicative m => Applicative (ChoiceT f m) where
+  pure a =
+    ChoiceT (\ _ -> pure a )
+  (ChoiceT lDeChooser) <*> (ChoiceT rDeChooser) =
+    ChoiceT (\ chooser -> lDeChooser chooser <*> rDeChooser chooser )
+
+instance Alternative m => Alternative (ChoiceT f m) where
+  empty = ChoiceT (const empty)
+  m1 <|> m2 = ChoiceT (\ chooser -> runChoiceT chooser m1 <|> runChoiceT chooser m2)
+
+instance Monad m => Monad (ChoiceT f m) where
+  (ChoiceT deChooser) >>= f =
+    ChoiceT (\ chooser -> deChooser chooser >>= (\ x -> runChoiceT chooser (f x)) )
+
+instance MonadPlus m => MonadPlus (ChoiceT f m)
+
+-- | 'ChoiceT' is a functor on the category of monads.
+-- However it is an invariant functor.  Meaning the traditional @mapChoiceT@ cannot be implemented.
+instance MonadTrans (ChoiceT f) where
+  lift m = ChoiceT (\ _ -> m )
+
+instance Monad m => MonadChoice f (ChoiceT f m) where
+  choose f = ChoiceT (\ chooser -> chooser f )
+
+instance MonadReader r m => MonadReader r (ChoiceT f m) where
+  ask = lift ask
+  local f = lowMap (local f)
+
+instance MonadState s m => MonadState s (ChoiceT f m) where
+  get = lift get
+  put s = lift (put s) 
+
+instance MonadWriter w m => MonadWriter w (ChoiceT f m) where
+  tell w = lift (tell w)
+  listen = lowMap listen
+  pass   = lowMap pass
+
+instance MonadIO m => MonadIO (ChoiceT f m) where
+  liftIO = lift . liftIO
+
+instance MonadError e m => MonadError e (ChoiceT f m) where
+  throwError toThrow = lift (throwError toThrow)
+  catchError m handler = ChoiceT (\ chooser -> catchError (runChoiceT chooser m) (runChoiceT chooser . handler))