diff --git a/Help/hsc3-dot.help.lhs b/Help/hsc3-dot.help.lhs
new file mode 100644
--- /dev/null
+++ b/Help/hsc3-dot.help.lhs
@@ -0,0 +1,34 @@
+> import Sound.SC3
+> import Sound.SC3.UGen.Dot
+
+Simple a-rate only graph.
+
+> draw (out 0 (sinOsc AR 440 0 * 0.1))
+
+With k-rate subgraph.
+
+> let f = lfSaw KR 1 0 * 220 + 440
+> in draw (out 0 (sinOsc AR f 0 * 0.1))
+
+With i-rate subgraph
+
+> do { l <- rand 200 400
+>    ; m <- rand l 600
+>    ; a <- rand 500 900
+>    ; let f = lfSaw KR 1 0 * m + a
+>      in draw (out 0 (sinOsc AR f 0 * 0.1)) }
+
+With control input
+
+> let f = Control KR "freq" 440
+> in draw (out 0 (sinOsc AR f 0 * 0.1))
+
+With multiple channel expansion.
+
+> let f = mce2 440 220
+> in draw (out 0 (sinOsc AR f 0 * 0.1))
+
+With multiple root graph.
+
+> let f = mce2 440 220
+> in draw (mrg [out 0 (sinOsc AR f 0 * 0.1), out 0 (sinOsc KR 1 0)])
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,12 @@
+hsc3-dot - haskell supercollider dot
+
+hsc3-dot provides dot graph drawing for SuperCollider unit generator
+graphs.
+
+  http://slavepianos.org/rd/
+  http://haskell.org/
+  http://audiosynth.com/
+  http://graphviz.org
+
+(c) rohan drape, 2006-2008
+    gpl, http://gnu.org/copyleft/
diff --git a/Setup.lhs b/Setup.lhs
new file mode 100644
--- /dev/null
+++ b/Setup.lhs
@@ -0,0 +1,3 @@
+#!/usr/bin/env runhaskell
+> import Distribution.Simple
+> main = defaultMain
diff --git a/Sound/SC3/UGen/Dot.hs b/Sound/SC3/UGen/Dot.hs
new file mode 100644
--- /dev/null
+++ b/Sound/SC3/UGen/Dot.hs
@@ -0,0 +1,148 @@
+-- | Module to provide graph drawing of unit generator graphs.  The
+--   output is in the form of a dot graph, which can be layed out
+--   using the @graphviz@ tools, see <http://graphviz.org>.
+module Sound.SC3.UGen.Dot ( dot, draw ) where
+
+import Control.Exception hiding (catch)
+import Data.List
+import Data.Maybe
+import Sound.SC3
+import System.IO
+import System.Cmd
+import System.Directory
+import System.Environment
+import System.FilePath
+
+-- | Generate the dot representation of the provided unit generator graph.
+dot :: UGen -> String
+dot r = 
+    let g = synth r
+        (Graph _ _ ks us) = g
+        ls = concat [ ["digraph Anonymous {"]
+                    , map dot_node_k ks
+                    , map (dot_node_u g) us
+                    , map (dot_edge g) (edges us)
+                    , ["}"] ]
+    in unlines ls
+
+-- | Draw the unit generator graph provided using the viewer at the
+--   environment variable @DOTVIEWER@, or @dotty@ if that variable is
+--   not defined.
+draw :: UGen -> IO ()
+draw u = get_dot_viewer >>= draw_with u
+
+data ToPort = ToPort Int Int
+              deriving (Eq, Show)
+
+type Edge = (FromPort, ToPort)
+type Edges = [Edge]
+
+find_node :: Graph -> Int -> Node
+find_node (Graph _ cs ks us) n =
+    fromJust (find (\x -> node_id x == n) (cs ++ ks ++ us))
+
+edges :: [Node] -> Edges
+edges = concatMap f
+    where f (NodeU x _ _ i _ _ _) = zip i (map (\n -> ToPort x n) [0..])
+          f _ = error "edges"
+
+record :: String -> String -> [[String]] -> String
+record lbl clr slt = concat [ lbl
+                            , " [shape=\"record\", "
+                            , "color=\"", clr, "\", "
+                            , "label=\"{", concat (g (map f slt)), "}\"];" ]
+    where f l = concat ["{", concat (g l), "}"]
+          g l = (intersperse "|" l)
+
+label :: Node -> String
+label (NodeC n _) = "N_" ++ show n
+label (NodeK n _ _ _ ) = "C_" ++ show n
+label (NodeU n _ _ _ _ _ _) = "U_" ++ show n
+label (NodeP n _ _) = "U_" ++ show n
+
+port_nid :: FromPort -> Int
+port_nid (C n) = n
+port_nid (K n) = n
+port_nid (U n _) = n
+
+port_indx :: FromPort -> Int
+port_indx (U _ x) = x
+port_indx _ = 0
+
+is_node_c :: Node -> Bool
+is_node_c (NodeC _ _) = True
+is_node_c _ = False
+
+is_node_u :: Node -> Bool
+is_node_u (NodeU _ _ _ _ _ _ _) = True
+is_node_u _ = False
+
+dot_edge :: Graph -> Edge -> [Char]
+dot_edge g (l, ToPort ri rn)
+    = let ln = find_node g (port_nid l)
+      in if is_node_c ln
+         then ""
+         else concat [ label ln
+                     , if is_node_u ln
+                       then ":O_" ++ show (port_indx l)
+                       else ""
+                     , " -> "
+                     , label (find_node g ri)
+                     , ":I_"
+                     , show rn
+                     , ";" ]
+
+rate_color :: Rate -> String
+rate_color AR = "black"
+rate_color KR = "blue"
+rate_color IR = "yellow"
+rate_color DR = "red"
+
+input :: Graph -> FromPort -> Int -> String
+input g (C n) _ = show (node_c_value (find_node g n))
+input _ _ i = "<I_" ++ show i ++ ">"
+
+name :: String -> Int -> String
+name "UnaryOpUGen" n = unaryName n
+name "BinaryOpUGen" n = binaryName n
+name n _ = n
+
+is_implicit_control :: Node -> Bool
+is_implicit_control (NodeU x _ s _ _ _ _) = x == -1 && s == "Control"
+is_implicit_control _ = False
+
+dot_node_u :: Graph -> Node -> String
+dot_node_u g u = if is_implicit_control u
+                 then ""
+                 else record lbl clr [upr,lwr]
+    where lbl = label u
+          clr = rate_color (node_u_rate u)
+          i = node_u_inputs u
+          i' = length i - 1
+          (Special s) = node_u_special u
+          upr = name (node_u_name u) s : zipWith (input g) i [0..i']
+          o = length (node_u_outputs u) - 1
+          lwr = map (\j -> "<O_" ++ show j ++ ">") [0..o]
+
+dot_node_k :: Node -> String
+dot_node_k u = concat [ label u
+                      , "[shape=\"trapezium\", color=\""
+                      , rate_color (node_k_rate u)
+                      , "\",label=\""
+                      , node_k_name u, ":", show (node_k_default u)
+                      , "\"];" ]
+
+-- Draw the UGen graph and display using the specified viewer.
+draw_with :: UGen -> String -> IO ()
+draw_with u v =
+    do d <- getTemporaryDirectory
+       let f = d </> "hsc.dot"
+       bracket (openFile f WriteMode)
+               hClose
+               (flip hPutStr (dot u))
+       system $ v ++ " " ++ f
+       return ()
+
+-- Read the environment variable @DOTVIEWER@, the default value is @"dotty"@.
+get_dot_viewer :: IO String
+get_dot_viewer = catch (getEnv "DOTVIEWER") (\_ -> return "dotty")
diff --git a/hsc3-dot.cabal b/hsc3-dot.cabal
new file mode 100644
--- /dev/null
+++ b/hsc3-dot.cabal
@@ -0,0 +1,22 @@
+Name:              hsc3-dot
+Version:           0.5
+Synopsis:          haskell supercollider graph drawing
+Description:       dot format graph generator for unit generator graphs
+License:           GPL
+Category:          Sound
+Copyright:         (c) Rohan Drape, 2006-2008
+Author:            Rohan Drape
+Maintainer:        rd@slavepianos.org
+Stability:         Experimental
+Homepage:          http://slavepianos.org/rd/f/890257/
+Tested-With:       GHC==6.10.1
+Build-Type:        Simple
+Cabal-Version:     >= 1.2
+
+Data-files:        README
+                   Help/hsc3-dot.help.lhs
+
+Library
+  Build-Depends:   base, directory, filepath, hsc3 == 0.5, process
+  GHC-Options:     -Wall -fwarn-tabs
+  Exposed-modules: Sound.SC3.UGen.Dot