diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+Copyright (c) 2014 Allen Nelson
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/error-list.cabal b/error-list.cabal
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--- /dev/null
+++ b/error-list.cabal
@@ -0,0 +1,25 @@
+-- Initial error-list.cabal generated by cabal init.  For further
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                error-list
+version:             0.1.0.0
+synopsis:            A useful type for collecting error messages.
+-- description:
+homepage:            http://github.com/thinkpad20/error-list
+license:             MIT
+license-file:        LICENSE
+author:              Allen Nelson
+maintainer:          ithinkican@gmail.com
+-- copyright:
+category:            Control
+build-type:          Simple
+-- extra-source-files:
+cabal-version:       >=1.10
+
+library
+  exposed-modules:     Control.Exception.ErrorList
+  -- other-modules:
+  other-extensions:    LambdaCase, OverloadedStrings, NoMonomorphismRestriction, FlexibleContexts, TypeSynonymInstances, FlexibleInstances, ViewPatterns, NoImplicitPrelude, TypeFamilies
+  build-depends:       base >=4.8 && <4.9, mtl, text, text-render
+  hs-source-dirs:      src
+  default-language:    Haskell2010
diff --git a/src/Control/Exception/ErrorList.hs b/src/Control/Exception/ErrorList.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Exception/ErrorList.hs
@@ -0,0 +1,125 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE TypeFamilies #-}
+module Control.Exception.ErrorList (
+    ErrorList(..), EList(..),
+    throwError1, throwErrorC, addError1, addErrorC,
+    assert, assertC, wrapJust, withHandler, ifErrorDo, ifErrorReturn,
+    showError, showError', errorC, oneErrorC, firstSuccess,
+    inContext
+  ) where
+
+import qualified Prelude as P
+import Prelude (($), (.), map, Int, Double, Functor(..), Show(..),
+                Eq(..), Bool(..), Integer, Double, Monad(..), flip,
+                Maybe(..), Either(..), IO(..))
+import Control.Monad (liftM)
+import Control.Monad.Trans (MonadIO(..), lift)
+import Control.Monad.Except (ExceptT, MonadError(..), throwError, runExceptT)
+import Control.Applicative hiding (empty)
+import Data.Monoid
+import Data.Text (Text, pack, unpack)
+import qualified Data.Text as T
+import qualified GHC.Exts as Exts
+import Text.Render
+
+class Exts.IsList elist => ErrorList elist where
+  addError :: Text -> elist -> elist
+  oneError :: Text -> elist
+
+data EList = EList Text [Text] deriving (Show, Eq)
+
+instance Exts.IsList EList where
+  type Item EList = Text
+  fromList (e:es) = EList e es
+  fromList _ = P.error "No main message in error list"
+  toList (EList msg msgs) = msg:msgs
+
+instance ErrorList EList where
+  addError e (EList e' es) = EList e (e':es)
+  oneError e = EList e []
+
+--instance Monoid ErrorList where
+--  mempty = ErrorList mempty
+--  ErrorList el1 `mappend` ErrorList el2 = ErrorList (el1 <> el2)
+
+instance Render EList where
+  render (EList m msgs) = T.unlines $ "Error:" : map (sp <>) (m:msgs)
+    where sp = T.replicate 2 " "
+
+-- | Throws a single-message eror list.
+throwError1 :: (ErrorList e, MonadError e m) => Text -> m a
+throwError1 = throwError . oneError
+
+-- | Concatenates a list of strings and throws them as an error.
+throwErrorC :: (ErrorList e, MonadError e m) => [Text] -> m a
+throwErrorC = throwError1 . mconcat
+
+-- | Throws a new error with the given string added on.
+addError1 :: (ErrorList e, MonadError e m) => Text -> e -> m a
+addError1 msg = throwError . addError msg
+
+-- | Throws a new error with the concatenation of the argument added on.
+addErrorC :: (ErrorList e, MonadError e m) => [Text] -> e -> m a
+addErrorC list = addError1 (mconcat list)
+
+-- | Useful when the handler is more concise than the action.
+withHandler :: MonadError e m => (e -> m a) -> m a -> m a
+withHandler = flip catchError
+
+-- | Tries something and throws an error if it fails.
+inContext :: (ErrorList e, MonadError e m) => Text -> m a -> m a
+inContext ctx action = action `catchError` addError1 ctx
+
+-- | Wraps a successful result in a `Just` and a failure in a `Nothing`.
+wrapJust :: MonadError e m => m a -> m (Maybe a)
+wrapJust action = liftM Just action `ifErrorReturn` Nothing
+
+-- | Performs an action, returning the second argument if it fails.
+ifErrorReturn :: MonadError e m => m a -> a -> m a
+ifErrorReturn action a = action `ifErrorDo` return a
+
+-- | Specifies what to do if the given action fails.
+ifErrorDo :: MonadError e m => m a -> m a -> m a
+ifErrorDo action action' = action `catchError` \_ -> action'
+
+-- | If the test is false, throws an error with the given message.
+assert :: (ErrorList e, MonadError e m) => Bool -> Text -> m ()
+assert True _ = return ()
+assert False msg = throwError1 msg
+
+-- | Same as `assert`, but concatenates a text list.
+assertC :: (ErrorList e, MonadError e m) => Bool -> [Text] -> m ()
+assertC test = assert test . mconcat
+
+-- | Pretty-prints errors that use `Either`.
+showError :: (Render e, Render b) => (a -> Either e b) -> a -> IO ()
+showError func arg = case func arg of
+  Left e -> P.putStrLn $ unpack $ render e
+  Right x -> P.putStrLn $ unpack $ render x
+
+-- | Pretty-prints errors that use `Either`, appearing in tuples.
+showError' :: (Render e, Render b) => (a -> (Either e b, c)) -> a -> IO ()
+showError' func arg = case func arg of
+  (Left e, _) -> P.putStrLn $ unpack $ render e
+  (Right x, _) -> P.putStrLn $ unpack $ render x
+
+-- | Concatenates a list of `Text` and makes an error out of it.
+errorC :: [Text] -> a
+errorC = P.error . unpack . mconcat
+
+firstSuccess :: (ErrorList e, MonadError e m) => Text -> [m a] -> m a
+firstSuccess msg [] = throwError1 msg
+firstSuccess msg (a:as) = a `ifErrorDo` firstSuccess msg as
+
+-- | Pretty-prints an error list. Considers the first item of the list to
+-- be the "main" message; subsequent messages are listed after.
+--printErrors :: ErrorList e => e -> IO ()
+--printErrors (ErrorList err errs) = do
+--  P.putStrLn ("Error: " <> unpack err)
+--  P.mapM_ (P.putStrLn . unpack . ("  " <>)) errs
+
+-- | Same as `oneError` but concatenates its argument.
+oneErrorC :: ErrorList e => [Text] -> e
+oneErrorC = oneError . mconcat