diff --git a/.ghci b/.ghci
new file mode 100644
--- /dev/null
+++ b/.ghci
@@ -0,0 +1,1 @@
+:set -isrc -idist/build/autogen -optP-include -optPdist/build/autogen/cabal_macros.h
diff --git a/.gitignore b/.gitignore
new file mode 100644
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,9 @@
+dist
+docs
+wiki
+TAGS
+tags
+wip
+.DS_Store
+.*.swp
+.*.swo
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,28 @@
+language: haskell
+before_install:
+  # Uncomment whenever hackage is down.
+  # - mkdir -p ~/.cabal && cp config ~/.cabal/config && cabal update
+
+  # Try installing some of the build-deps with apt-get for speed.
+  - ./travis-cabal-apt-install --only-dependencies --force-reinstall $mode
+
+  - sudo apt-get -q -y install hlint || cabal install hlint
+
+install:
+  - cabal configure $mode
+  - cabal build
+
+script:
+  - $script
+  - hlint src --cpp-define HLINT
+
+notifications:
+  irc:
+    channels:
+      - "irc.freenode.org#haskell-lens"
+    skip_join: true
+    template:
+      - "\x0313transformers-compat\x03/\x0306%{branch}\x03 \x0314%{commit}\x03 %{build_url} %{message}"
+
+env:
+  - mode="--enable-tests" script="cabal test"
diff --git a/.vim.custom b/.vim.custom
new file mode 100644
--- /dev/null
+++ b/.vim.custom
@@ -0,0 +1,31 @@
+" Add the following to your .vimrc to automatically load this on startup
+
+" if filereadable(".vim.custom")
+"     so .vim.custom
+" endif
+
+function StripTrailingWhitespace()
+  let myline=line(".")
+  let mycolumn = col(".")
+  silent %s/  *$//
+  call cursor(myline, mycolumn)
+endfunction
+
+" enable syntax highlighting
+syntax on
+
+" search for the tags file anywhere between here and /
+set tags=TAGS;/
+
+" highlight tabs and trailing spaces
+set listchars=tab:‗‗,trail:‗
+set list
+
+" f2 runs hasktags
+map <F2> :exec ":!hasktags -x -c --ignore src"<CR><CR>
+
+" strip trailing whitespace before saving
+" au BufWritePre *.hs,*.markdown silent! cal StripTrailingWhitespace()
+
+" rebuild hasktags after saving
+au BufWritePost *.hs silent! :exec ":!hasktags -x -c --ignore src"
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.markdown
@@ -0,0 +1,3 @@
+0.1
+---
+* Repository initialized by pulling the `transformers-0.2` compatibility layer out of `lens`.
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright 2012 Edward Kmett
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+3. Neither the name of the author nor the names of his contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.markdown b/README.markdown
new file mode 100644
--- /dev/null
+++ b/README.markdown
@@ -0,0 +1,17 @@
+transformers-compat
+===================
+
+[![Build Status](https://secure.travis-ci.org/ekmett/transformers-compat.png?branch=master)](http://travis-ci.org/ekmett/transformers-compat)
+
+This provides a thin compatibility shim on top of transformers-0.2 to add the types that were added in transformers-0.3.
+
+This enables users to maintain haskell-platform compatibility, while still gaining access ot the new functionality.
+
+Contact Information
+-------------------
+
+Contributions and bug reports are welcome!
+
+Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.
+
+-Edward Kmett
diff --git a/Setup.lhs b/Setup.lhs
new file mode 100644
--- /dev/null
+++ b/Setup.lhs
@@ -0,0 +1,7 @@
+#!/usr/bin/runhaskell
+> module Main (main) where
+
+> import Distribution.Simple
+
+> main :: IO ()
+> main = defaultMain
diff --git a/config b/config
new file mode 100644
--- /dev/null
+++ b/config
@@ -0,0 +1,16 @@
+-- This provides a custom ~/.cabal/config file for use when hackage is down that should work on unix
+--
+-- This is particularly useful for travis-ci to get it to stop complaining
+-- about a broken build when everything is still correct on our end.
+--
+-- This uses Luite Stegeman's mirror of hackage provided by his 'hdiff' site instead
+--
+-- To enable this, uncomment the before_script in .travis.yml
+
+remote-repo: hdiff.luite.com:http://hdiff.luite.com/packages/archive
+remote-repo-cache: ~/.cabal/packages
+world-file: ~/.cabal/world
+build-summary: ~/.cabal/logs/build.log
+remote-build-reporting: anonymous
+install-dirs user
+install-dirs global
diff --git a/src/Control/Applicative/Backwards.hs b/src/Control/Applicative/Backwards.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Applicative/Backwards.hs
@@ -0,0 +1,51 @@
+-- |
+-- Module      :  Control.Applicative.Backwards
+-- Copyright   :  (c) Russell O'Connor 2009
+-- License     :  BSD-style (see the file LICENSE)
+--
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Making functors with an 'Applicative' instance that performs actions
+-- in the reverse order.
+--
+-- NB: This module is only included in @lens@ for backwards compatibility with
+-- @transformers@ versions before 3.0.
+module Control.Applicative.Backwards where
+
+import Prelude hiding (foldr, foldr1, foldl, foldl1)
+import Control.Applicative
+import Data.Foldable
+import Data.Traversable
+
+-- | The same functor, but with an 'Applicative' instance that performs
+-- actions in the reverse order.
+newtype Backwards f a = Backwards { forwards :: f a }
+
+-- | Derived instance.
+instance (Functor f) => Functor (Backwards f) where
+    fmap f (Backwards a) = Backwards (fmap f a)
+
+-- | Apply @f@-actions in the reverse order.
+instance (Applicative f) => Applicative (Backwards f) where
+    pure a = Backwards (pure a)
+    Backwards f <*> Backwards a = Backwards (a <**> f)
+
+-- | Try alternatives in the same order as @f@.
+instance (Alternative f) => Alternative (Backwards f) where
+    empty = Backwards empty
+    Backwards x <|> Backwards y = Backwards (x <|> y)
+
+-- | Derived instance.
+instance (Foldable f) => Foldable (Backwards f) where
+    foldMap f (Backwards t) = foldMap f t
+    foldr f z (Backwards t) = foldr f z t
+    foldl f z (Backwards t) = foldl f z t
+    foldr1 f (Backwards t) = foldl1 f t
+    foldl1 f (Backwards t) = foldr1 f t
+
+-- | Derived instance.
+instance (Traversable f) => Traversable (Backwards f) where
+    traverse f (Backwards t) = fmap Backwards (traverse f t)
+    sequenceA (Backwards t) = fmap Backwards (sequenceA t)
diff --git a/src/Control/Applicative/Lift.hs b/src/Control/Applicative/Lift.hs
new file mode 100644
--- /dev/null
+++ b/src/Control/Applicative/Lift.hs
@@ -0,0 +1,71 @@
+-- |
+-- Module      :  Control.Applicative.Lift
+-- Copyright   :  (c) Ross Paterson 2010
+-- License     :  BSD-style (see the file LICENSE)
+--
+-- Maintainer  :  ross@soi.city.ac.uk
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Adding a new kind of pure computation to an applicative functor.
+--
+-- NB: This module is only included in @lens@ for backwards compatibility with
+-- @transformers@ versions before 3.0.
+
+module Control.Applicative.Lift (
+    Lift(..), unLift,
+    -- * Collecting errors
+    Errors, failure
+  ) where
+
+import Control.Applicative
+import Data.Foldable (Foldable(foldMap))
+import Data.Functor.Constant
+import Data.Monoid
+import Data.Traversable (Traversable(traverse))
+
+-- | Applicative functor formed by adding pure computations to a given
+-- applicative functor.
+data Lift f a = Pure a | Other (f a)
+
+instance (Functor f) => Functor (Lift f) where
+    fmap f (Pure x) = Pure (f x)
+    fmap f (Other y) = Other (fmap f y)
+
+instance (Foldable f) => Foldable (Lift f) where
+    foldMap f (Pure x) = f x
+    foldMap f (Other y) = foldMap f y
+
+instance (Traversable f) => Traversable (Lift f) where
+    traverse f (Pure x) = Pure <$> f x
+    traverse f (Other y) = Other <$> traverse f y
+
+-- | A combination is 'Pure' only if both parts are.
+instance (Applicative f) => Applicative (Lift f) where
+    pure = Pure
+    Pure f <*> Pure x = Pure (f x)
+    Pure f <*> Other y = Other (f <$> y)
+    Other f <*> Pure x = Other (($ x) <$> f)
+    Other f <*> Other y = Other (f <*> y)
+
+-- | A combination is 'Pure' only either part is.
+instance Alternative f => Alternative (Lift f) where
+    empty = Other empty
+    Pure x <|> _ = Pure x
+    Other _ <|> Pure y = Pure y
+    Other x <|> Other y = Other (x <|> y)
+
+-- | Projection to the other functor.
+unLift :: Applicative f => Lift f a -> f a
+unLift (Pure x) = pure x
+unLift (Other e) = e
+
+-- | An applicative functor that collects a monoid (e.g. lists) of errors.
+-- A sequence of computations fails if any of its components do, but
+-- unlike monads made with 'ErrorT' from "Control.Monad.Trans.Error",
+-- these computations continue after an error, collecting all the errors.
+type Errors e = Lift (Constant e)
+
+-- | Report an error.
+failure :: Monoid e => e -> Errors e a
+failure e = Other (Constant e)
diff --git a/src/Data/Functor/Reverse.hs b/src/Data/Functor/Reverse.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Functor/Reverse.hs
@@ -0,0 +1,57 @@
+-- |
+-- Module      :  Data.Functor.Reverse
+-- Copyright   :  (c) Russell O'Connor 2009
+-- License     :  BSD-style (see the file LICENSE)
+--
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Making functors whose elements are notionally in the reverse order
+-- from the original functor.
+--
+-- /NB:/ Note this module is only included in @lens@ for backwards
+-- compatibility with older @containers@ versions.
+
+module Data.Functor.Reverse where
+
+import Control.Applicative.Backwards
+
+import Prelude hiding (foldr, foldr1, foldl, foldl1)
+import Control.Applicative
+import Data.Foldable
+import Data.Traversable
+import Data.Monoid
+
+-- | The same functor, but with 'Foldable' and 'Traversable' instances
+-- that process the elements in the reverse order.
+newtype Reverse f a = Reverse { getReverse :: f a }
+
+-- | Derived instance.
+instance (Functor f) => Functor (Reverse f) where
+    fmap f (Reverse a) = Reverse (fmap f a)
+
+-- | Derived instance.
+instance (Applicative f) => Applicative (Reverse f) where
+    pure a = Reverse (pure a)
+    Reverse f <*> Reverse a = Reverse (f <*> a)
+
+-- | Derived instance.
+instance (Alternative f) => Alternative (Reverse f) where
+    empty = Reverse empty
+    Reverse x <|> Reverse y = Reverse (x <|> y)
+
+-- | Fold from right to left.
+instance (Foldable f) => Foldable (Reverse f) where
+    foldMap f (Reverse t) = getDual (foldMap (Dual . f) t)
+    foldr f z (Reverse t) = foldl (flip f) z t
+    foldl f z (Reverse t) = foldr (flip f) z t
+    foldr1 f (Reverse t) = foldl1 (flip f) t
+    foldl1 f (Reverse t) = foldr1 (flip f) t
+
+-- | Traverse from right to left.
+instance (Traversable f) => Traversable (Reverse f) where
+    traverse f (Reverse t) =
+        fmap Reverse . forwards $ traverse (Backwards . f) t
+    sequenceA (Reverse t) =
+        fmap Reverse . forwards $ sequenceA (fmap Backwards t)
diff --git a/transformers-compat.cabal b/transformers-compat.cabal
new file mode 100644
--- /dev/null
+++ b/transformers-compat.cabal
@@ -0,0 +1,60 @@
+name:          transformers-compat
+category:      Compatibility
+version:       0.1
+license:       BSD3
+cabal-version: >= 1.8
+license-file:  LICENSE
+author:        Edward A. Kmett
+maintainer:    Edward A. Kmett <ekmett@gmail.com>
+stability:     provisional
+homepage:      http://github.com/ekmett/transformers-compat/
+bug-reports:   http://github.com/ekmett/transformers-compat/issues
+copyright:     Copyright (C) 2012 Edward A. Kmett
+synopsis:      Lenses, Folds and Traversals
+description:
+  This package includes backported versions of types that were added
+  to transformers in transformers 0.3 for users who need strict
+  transformers 0.2 compatibility to run on old versions of the
+  platform, but also need those types.
+  .
+  Those users should be able to just depend on @transformers >= 0.2@
+  and @transformers-compat@.
+  .
+  Note: missing methods are not supplied
+  but this at least permits the types to be used.
+
+build-type:    Simple
+tested-with:   GHC == 7.0.4, GHC == 7.4.1, GHC == 7.4.2, GHC == 7.6.1
+extra-source-files:
+  .travis.yml
+  .ghci
+  .gitignore
+  .vim.custom
+  config
+  README.markdown
+  CHANGELOG.markdown
+
+source-repository head
+  type: git
+  location: git://github.com/ekmett/transformers-compat.git
+
+flag transformers2
+  default: False
+  manual: False
+
+library
+  build-depends:
+    base >= 4.3 && < 5
+
+  hs-source-dirs: src
+
+  if flag(transformers2)
+    build-depends:
+      transformers >= 0.2 && < 0.3
+    exposed-modules:
+      Control.Applicative.Backwards
+      Control.Applicative.Lift
+      Data.Functor.Reverse
+  else
+    build-depends:
+      transformers >= 0.3 && < 0.4