diff --git a/Data/Measure/Angle.hs b/Data/Measure/Angle.hs
new file mode 100644
--- /dev/null
+++ b/Data/Measure/Angle.hs
@@ -0,0 +1,104 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving, MultiParamTypeClasses #-}
+
+-- | For measuring the vertex of angles.
+--
+-- @
+--     Data.Measure.Angle\> 127 ..> degrees <.. radians
+--     2.2165681500327987
+-- @
+--
+-- @
+--     Data.Measure.Angle\> 2478 ..> mils <.. grads
+--     154.875
+-- @
+--
+-- @
+--     Data.Measure.Angle\> 24 ..> arcminutes <.. sextants
+--     6.666666666666666e-3
+-- @
+module Data.Measure.Angle(AngleMeasure,
+                          rad,
+                          radians,
+                          degrees,
+                          mils,
+                          arcminutes,
+                          arcseconds,
+                          grads,
+                          octants,
+                          quadrants,
+                          sextants,
+                          signs,
+                          Angle,
+                          rad',
+                          angle) where
+
+import Data.Measure.RelativeDouble
+import Data.Measure.ConvertDouble
+
+-- | A ratio of measurement of an angle.
+newtype AngleMeasure = Radian {
+  rad :: Double -- ^ The ratio of measurement of an angle in radians.
+} deriving (Eq, Ord, Enum, Num, Fractional, Floating)
+
+instance Show AngleMeasure where
+  show = show . rad
+
+-- | A measurement of angles.
+radians :: AngleMeasure
+radians = Radian 1
+
+-- | A measurement of angles in degrees.
+degrees :: AngleMeasure
+degrees = radians .*. pi / 180
+
+-- | A measurement of angular mils.
+mils :: AngleMeasure
+mils = radians .*. pi / 3200
+
+-- | A measurement of arcminutes.
+arcminutes :: AngleMeasure
+arcminutes = degrees ./. 60
+
+-- | A measurement of arcseconds.
+arcseconds :: AngleMeasure
+arcseconds = arcminutes ./. 60
+
+-- | A measurement of grads.
+grads :: AngleMeasure
+grads = radians .*. pi / 200
+
+-- | A measurement of octants.
+octants :: AngleMeasure
+octants = degrees .*. 45
+
+-- | A measurement of quadrants.
+quadrants :: AngleMeasure
+quadrants = octants .*. 2
+
+-- | A measurement of sextants.
+sextants :: AngleMeasure
+sextants = degrees .*. 60
+
+-- | A measurement of signs.
+signs :: AngleMeasure
+signs = degrees .*. 30
+
+-- | A measurement of an angle in radians.
+newtype Angle = Angle {
+  rad' :: Double -- ^ The measurement of an angle in radians.
+} deriving (Eq, Ord, Enum, Num, Fractional, Floating)
+
+-- | Construct an @Angle@ from a floating-point value.
+angle :: Double -> Angle
+angle = Angle
+
+instance Show Angle where
+  show (Angle d) = show d ++ "rad"
+
+instance RelativeDouble AngleMeasure where
+  Radian n .*. r = Radian (n * r)
+  Radian n ./. r = Radian (n / r)
+
+instance ConvertDouble AngleMeasure Angle where
+  x ..> n = Angle (x * rad n)
+  n <.. x = rad' n / rad x
diff --git a/Data/Measure/ConvertDouble.hs b/Data/Measure/ConvertDouble.hs
new file mode 100644
--- /dev/null
+++ b/Data/Measure/ConvertDouble.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies #-}
+
+-- | A measurement that is represented by a floating-point value that can be converted by differing units.
+module Data.Measure.ConvertDouble where
+
+class ConvertDouble u v | u -> v where
+  (..>) :: Double -> u -> v -- ^ Convert to a unit of measurement.
+  (<..) :: v -> u -> Double -- ^ Convert from a unit of measurement.
diff --git a/Data/Measure/Length.hs b/Data/Measure/Length.hs
new file mode 100644
--- /dev/null
+++ b/Data/Measure/Length.hs
@@ -0,0 +1,219 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving, MultiParamTypeClasses #-}
+
+-- | For measuring length, the distance between two points.
+--
+-- @
+--     Data.Measure.Length\> 27 ..> miles <.. metres
+--     43452.288
+-- @
+--
+-- @
+--     Data.Measure.Length\> 14.6 ..> kilometres <.. nauticalMiles
+--     7.883369330453564
+-- @
+--
+-- @
+--     Data.Measure.Length\> 14.6 ..> parsecs <.. kilometres
+--     4.5050896172e14
+-- @
+module Data.Measure.Length(LengthMeasure,
+                           nm,
+                           yoctometres,
+                           zeptometres,
+                           attometres,
+                           femtometres,
+                           fermis,
+                           picometres,
+                           nanometres,
+                           micrometres,
+                           millimetres,
+                           centimetres,
+                           decimetres,
+                           metres,
+                           kilometres,
+                           au,
+                           lightSeconds,
+                           lightMinutes,
+                           lightHours,
+                           lightDays,
+                           lightYears,
+                           parsecs,
+                           ells,
+                           inches,
+                           thou,
+                           feet,
+                           yards,
+                           quarters,
+                           miles,
+                           nauticalMiles,
+                           nauticalMilesAdmiralty,
+                           fathoms,
+                           cables,
+                           chains,
+                           furlongs,
+                           Length,
+                           nm',
+                           length') where
+
+import Data.Measure.RelativeDouble
+import Data.Measure.ConvertDouble
+
+-- | A ratio of measurement of length to nanometres.
+newtype LengthMeasure = Nanometre {
+  nm :: Double -- ^ The ratio of measurement of length in nanometres.
+} deriving (Eq, Ord, Enum, Num, Fractional, Floating)
+
+instance Show LengthMeasure where
+  show = show . nm
+
+-- | A measurement of length, 10 ^ -24 metres.
+yoctometres :: LengthMeasure
+yoctometres = zeptometres ./. 1000
+
+-- | A measurement of length, 10 ^ -21 metres.
+zeptometres :: LengthMeasure
+zeptometres = attometres ./. 1000
+
+-- | A measurement of length, 10 ^ -18 metres.
+attometres :: LengthMeasure
+attometres = femtometres ./. 1000
+
+-- | A measurement of length, 10 ^ -15 metres.
+femtometres :: LengthMeasure
+femtometres = picometres ./. 1000
+
+-- | A measurement of length, 10 ^ -15 metres.
+fermis :: LengthMeasure
+fermis = femtometres
+
+-- | A measurement of length, 10 ^ -12 metres.
+picometres :: LengthMeasure
+picometres = nanometres ./. 1000
+
+-- | A measurement of length, 10 ^ -9 metres.
+nanometres :: LengthMeasure
+nanometres = Nanometre 1
+
+-- | A measurement of length, 10 ^ -6 metres.
+micrometres :: LengthMeasure
+micrometres = nanometres .*. 1000
+
+-- | A measurement of length, 10 ^ -3 metres.
+millimetres :: LengthMeasure
+millimetres = micrometres .*. 1000
+
+-- | A measurement of length, 10 ^ -2 metres.
+centimetres :: LengthMeasure
+centimetres = millimetres .*. 10
+
+-- | A measurement of length, 10 ^ -1 metres.
+decimetres :: LengthMeasure
+decimetres = centimetres .*. 10
+
+-- | A measurement of length.
+metres :: LengthMeasure
+metres = millimetres .*. 1000
+
+-- | A measurement of length, 10 ^ 3 metres.
+kilometres :: LengthMeasure
+kilometres = metres .*. 1000
+
+-- | A measurement of length, Astronomical Units.
+au :: LengthMeasure
+au = metres .*. 149597871464
+
+-- | A measurement of length, the distance light travels in a vaccuum in one second.
+lightSeconds :: LengthMeasure
+lightSeconds = metres .*. 299792458
+
+-- | A measurement of length, the distance light travels in a vaccuum in one minute.
+lightMinutes :: LengthMeasure
+lightMinutes = lightSeconds .*. 60
+
+-- | A measurement of length, the distance light travels in a vaccuum in one hour.
+lightHours :: LengthMeasure
+lightHours = lightMinutes .*. 60
+
+-- | A measurement of length, the distance light travels in a vaccuum in one day.
+lightDays :: LengthMeasure
+lightDays = lightHours .*. 24
+
+-- | A measurement of length, the distance light travels in a vaccuum in one (Julian) year.
+lightYears :: LengthMeasure
+lightYears = metres .*. 9460730472580800
+
+-- | A measurement of length, parallax of one arcsecond.
+parsecs :: LengthMeasure
+parsecs = kilometres .*. 30856778200000
+
+-- | A measurement of length, approximating the length of a man's arm.
+ells :: LengthMeasure
+ells = metres .*. 1.143
+
+-- | A measurement of length, 25.4 millimetres.
+inches :: LengthMeasure
+inches = millimetres .*. 25.4
+
+-- | A measurement of length, 0.0254 millimetres.
+thou :: LengthMeasure
+thou = inches ./. 1000
+
+-- | A measurement of length, 12 inches.
+feet :: LengthMeasure
+feet = inches .*. 12
+
+-- | A measurement of length, 3 feet.
+yards :: LengthMeasure
+yards = feet .*. 3
+
+-- | A measurement of length, a quarter of a yard.
+quarters :: LengthMeasure
+quarters = yards ./. 4
+
+-- | A measurement of length, 1760 yards.
+miles :: LengthMeasure
+miles = yards .*. 1760
+
+-- | A measurement of length, 1852 metres.
+nauticalMiles :: LengthMeasure
+nauticalMiles = metres .*. 1852
+
+-- | A measurement of length, 6080 feet.
+nauticalMilesAdmiralty :: LengthMeasure
+nauticalMilesAdmiralty = feet .*. 6080
+
+-- | A measurement of length, 1828.8 millimetres.
+fathoms :: LengthMeasure
+fathoms = micrometres .*. 1828800
+
+-- | A measurement of length, 100 fathoms.
+cables :: LengthMeasure
+cables = fathoms .*. 100
+
+-- | A measurement of length, 66 feet.
+chains :: LengthMeasure
+chains = feet .*. 66
+
+-- | A measurement of length, 10 chains.
+furlongs :: LengthMeasure
+furlongs = chains .*. 10
+
+-- | A measurement of length in nanometres.
+newtype Length = Length {
+  nm' :: Double -- ^ The number of nanometres.
+} deriving (Eq, Ord, Enum, Num, Fractional, Floating)
+
+-- | Construct a @Length@ from a floating-point value.
+length' :: Double -> Length
+length' = Length
+
+instance Show Length where
+  show (Length d) = show d ++ "nm"
+
+instance RelativeDouble LengthMeasure where
+  Nanometre n .*. r = Nanometre (n * r)
+  Nanometre n ./. r = Nanometre (n / r)
+
+instance ConvertDouble LengthMeasure Length where
+  x ..> n = Length (x * nm n)
+  n <.. x = nm' n / nm x
diff --git a/Data/Measure/RelativeDouble.hs b/Data/Measure/RelativeDouble.hs
new file mode 100644
--- /dev/null
+++ b/Data/Measure/RelativeDouble.hs
@@ -0,0 +1,7 @@
+-- | A measurement that is relative to another by a floating-point value.
+module Data.Measure.RelativeDouble where
+
+-- | A class of data types that are a measurement relative by a floating-point value.
+class RelativeDouble t where
+  (.*.) :: t -> Double -> t -- ^ Relative by a product.
+  (./.) :: t -> Double -> t -- ^ Relative by a quotient.
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,27 @@
+Copyright 2009 Tony Morris
+
+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 REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL THE 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/Measure.cabal b/Measure.cabal
new file mode 100644
--- /dev/null
+++ b/Measure.cabal
@@ -0,0 +1,28 @@
+Name:               Measure
+Version:            0.0.1
+License:            BSD3
+License-File:       LICENSE
+Author:             Tony Morris <code@tmorris.net>
+Maintainer:         Tony Morris
+Synopsis:           A library for units of measurement
+Category:           Development
+Description:        A library for units of measurement
+Cabal-version:      >= 1.2
+Build-Type:         Simple
+Extra-Source-Files: README
+
+Flag small_base
+  Description:     Choose the new, split-up base package.
+
+Library
+  if flag(small_base)
+    Build-Depends: base < 4 && >= 3
+  else
+    Build-Depends: base < 3
+
+  GHC-Options:    -Wall
+  Exposed-Modules:
+          Data.Measure.Length,
+          Data.Measure.Angle,
+          Data.Measure.RelativeDouble,
+          Data.Measure.ConvertDouble
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,7 @@
+Measure
+=======
+
+A library for units of measurement. Currently only measurement of length and angles are supported. Suggestions are welcome regarding the design of the library, particularly the type-classes and use of types. See the haddock for usage examples.
+
+Tony Morris
+code@tmorris.net
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,3 @@
+import Distribution.Simple
+main = defaultMain
+