diff --git a/CCMain.hs b/CCMain.hs
--- a/CCMain.hs
+++ b/CCMain.hs
@@ -1,7 +1,10 @@
 ------------------------------------------------------------------------------------------
--- CleverCSS in Haskell, (c) 2007, 2008 Georg Brandl. Licensed under the BSD license.
+-- |
+-- Module      :  CCMain
+-- Copyright   :  (c) 2007-2010 Georg Brandl
+-- License     :  BSD (see the file LICENSE)
 --
--- CCMain module: command-line interface.
+-- Command-line interface for CleverCSS.
 ------------------------------------------------------------------------------------------
 
 module Main (main) where
diff --git a/Text/CSS/CleverCSS.hs b/Text/CSS/CleverCSS.hs
--- a/Text/CSS/CleverCSS.hs
+++ b/Text/CSS/CleverCSS.hs
@@ -1,10 +1,14 @@
 ------------------------------------------------------------------------------------------
--- CleverCSS in Haskell, (c) 2007, 2008 Georg Brandl. Licensed under the BSD license.
---
--- Text.CSS.CleverCSS module: main parsing and evaluation.
+-- |
+-- Module      :  Text.CSS.CleverCSS
+-- Copyright   :  (c) 2007-2010 Georg Brandl
+-- License     :  BSD (see the file LICENSE)
 --
--- TODO: properly parse selectors before splitting them
+-- Main parsing and evaluation module for CleverCSS.
 ------------------------------------------------------------------------------------------
+
+-- TODO: properly parse selectors before splitting them
+
 {-# LANGUAGE PatternGuards, TypeSynonymInstances, CPP #-}
 
 module Text.CSS.CleverCSS (cleverCSSConvert) where
@@ -14,7 +18,6 @@
 import Control.Monad.RWS
 import Data.Char (toUpper, toLower)
 import Data.List (findIndex)
-import Data.Ratio
 import Data.Sequence (Seq, singleton)
 import Text.Printf (printf)
 import Text.ParserCombinators.Parsec hiding (newline)
@@ -60,7 +63,7 @@
           | ExprList [Expr]                          -- x, y, z
           | Subseq [Expr]                            -- x y z
           | Call Expr !String (Maybe Expr)           -- x.y([z])
-          | Var !String                              -- $x
+          | Var !String                              -- \$x
           | Bare !String                             -- x
           | String !String                           -- "x"
           | CSSFunc !String Expr                     -- url(x)
@@ -109,8 +112,8 @@
   show (ExprList l)        = joinShow ", " l
   show (Subseq l)          = joinShow " " l
   show (String s)          = cssShow s
-  show (Number n)          = showRational n
-  show (Dim (n, u))        = showRational n ++ u
+  show (Number n)          = showRat n
+  show (Dim (n, u))        = showRat n ++ u
   show (CSSFunc name args) = name ++ "(" ++ show args ++ ")"
   show (Color (Left n))    = n
   show (Color (Right (r,g,b))) = case Map.lookup (r,g,b) reverse_colors of
@@ -118,12 +121,6 @@
                                    Nothing -> printf "#%02x%02x%02x" r g b
   show (Bare s)            = s
 
-showRational r | rest == 0 = show whole
-               | otherwise = show (fromRational r)
-  where d = denominator r
-        n = numerator r
-        (whole, rest) = n `divMod` d
-
 ------------------------------------------------------------------------------------------
 -- the tokenizer and parser
 
@@ -553,6 +550,7 @@
 findError2 cons xs = head $ [Error e | Error e <- xs] ++ [cons xs]
 
 -- evaluate a string
+evalString :: Dict Expr -> SourceName -> String -> Expr
 evalString varmap source string = case runParser exprseq [] "" string of
   Left err  -> Error $ showWithoutPos ("in " ++ source ++ ":") err
   Right []  -> String ""
@@ -581,7 +579,13 @@
   formatProp (Property _ _ _) = error "property has not exactly one value"
   formatProp _ = error "remaining subitems in block"
 
-cleverCSSConvert :: SourceName -> String -> [(String, String)] -> IO (Either String String)
+-- | Convert CleverCSS source to CSS.
+--   For documentation of available syntax and command line use, see
+--   <http://sandbox.pocoo.org/clevercss-hs/>.
+cleverCSSConvert :: SourceName                 -- ^ source (file) name
+                 -> String                     -- ^ CleverCSS input
+                 -> [(String, String)]         -- ^ initial variable assignments
+                 -> IO (Either String String)  -- ^ CSS output
 cleverCSSConvert name input initial_map =
   case runParser parser [0] name (preprocess input) of
       Left err    -> return . Left $ "Parse error " ++ show err
diff --git a/Text/CSS/CleverCSSUtil.hs b/Text/CSS/CleverCSSUtil.hs
--- a/Text/CSS/CleverCSSUtil.hs
+++ b/Text/CSS/CleverCSSUtil.hs
@@ -1,7 +1,10 @@
-------------------------------------------------------------------------------------------
--- CleverCSS in Haskell, (c) 2007, 2008 Georg Brandl. Licensed under the BSD license.
+-----------------------------------------------------------------------------------------
+-- |
+-- Module      :  Text.CSS.CleverCSSUtil
+-- Copyright   :  (c) 2007-2010 Georg Brandl
+-- License     :  BSD (see the file LICENSE)
 --
--- Text.CSS.CleverCSSUtil module: utilities.
+-- CleverCSS utilities.
 ------------------------------------------------------------------------------------------
 
 module Text.CSS.CleverCSSUtil (
@@ -11,12 +14,11 @@
              unitconv, inrange, readNum, readDim,
              trim, ltrim, rtrim, split, joinStr, joinShow,
              preprocess, hexToString, cssShow, showWithoutPos,
-             ratMod, roundRat,
+             ratMod, roundRat, showRat
             ) where
 
 import Control.Arrow ((&&&))
 import Control.Monad (msum)
-import Data.Char
 import Data.List hiding (partition)
 import Data.Ratio ((%), numerator, denominator)
 import Numeric (readFloat)
@@ -344,3 +346,8 @@
 roundRat num places =
     let exp = round places :: Integer in
     (round (num * (10^exp))) % (10^exp) -- XXX todo
+
+showRat :: Rational -> String
+showRat r | rest == 0 = show whole
+          | otherwise = printf "%f" (fromRational r :: Double)
+  where (whole, rest) = (denominator r) `divMod` (numerator r)
diff --git a/clevercss.cabal b/clevercss.cabal
--- a/clevercss.cabal
+++ b/clevercss.cabal
@@ -1,6 +1,6 @@
 cabal-version: >=1.2
 Name: clevercss
-Version: 0.2
+Version: 0.2.1
 Category: Text
 Synopsis: A CSS preprocessor
 Description: CleverCSS is a CSS preprocessing library that allows defining variables and nesting selectors so that you don't need to Repeat Yourself.