diff --git a/FracComp.hs b/FracComp.hs
--- a/FracComp.hs
+++ b/FracComp.hs
@@ -4,6 +4,9 @@
 
 import Graphics.UI.GLUT
 import Data.Array.IO
+import Control.Concurrent
+import Control.Exception
+import System.IO.Unsafe
 
 import FracState
 
@@ -14,21 +17,8 @@
 mandPoint !n !x !y cx cy mi | n > mi		   = 0.0
 					        | (x2 + y2) > 4.0  = 1.0 - logBase 2 (0.5 * logBase 2 (x2 + y2)) + fromIntegral n
 					        | otherwise		   = mandPoint (n+1) (x2 - y2 + cx) (2.0*x*y + cy) cx cy mi where
-	x2 = x*x  --This CSE saves a few cycles
-	y2 = y*y
-
-compPoints :: Double -> Double -> Double -> Int -> Sz -> Pix -> IO ()
-compPoints xm ym rng mi sz@(Sz width height) arr = go 0 0 where
-	go !x !y | y == height  = return () 
-			 | x == width   = go 0 (y+1)
-			 | otherwise = do 
-		writeArray arr k (mandPoint 0 0.0 0.0 cx cy mi)
-		go (x+1) y where
-			k = x + y*width
-			fi = fromIntegral
-			cx = rng * (fi x - fi w2) / fi w2 + xm :: Double
-			cy = rng * (fi y - fi h2) / fi h2 + ym :: Double
-			(w2, h2) = (width `div` 2, height `div` 2)
+	!x2 = x*x  --This CSE saves a few cycles
+	!y2 = y*y
 
 -- Colour a vertex
 colourMand :: Double -> Double -> Color3 GLdouble
@@ -37,6 +27,44 @@
 	r = 0.5 + 0.5 * cos (m * cm) 
 	g = 0.5 + 0.5 * cos ((m + 16.0) * cm)
 	b = 0.5 + 0.5 * cos ((m + 32.0) * cm)
+
+children :: MVar [MVar ()]
+children = unsafePerformIO (newMVar [])
+
+waitForChildren :: IO ()
+waitForChildren = do
+	cs <- takeMVar children
+	case cs of
+		[]   -> do
+			putMVar children []
+			return ()
+		m:ms -> do
+			putMVar children ms
+			takeMVar m
+			waitForChildren
+
+forkChild :: IO () -> IO ThreadId
+forkChild io = do
+	mvar <- newEmptyMVar
+	childs <- takeMVar children
+	putMVar children (mvar:childs)
+	forkIO (io `finally` putMVar mvar ())
+
+compPoints :: Double -> Double -> Double -> Int -> Sz -> Pix -> IO ()
+compPoints xm ym rng mi sz@(Sz width height) arr = do
+	go 0
+	waitForChildren where
+		go !y | y == height = return () 
+			  | otherwise = forkChild (goRow 0 y) >> go (y+1)
+		goRow !x y  | x == width  = return () :: IO ()
+					| otherwise = do	
+			writeArray arr k (mandPoint 0 0.0 0.0 cx cy mi)
+			goRow (x+1) y where
+				k = x + y*width
+				fi = fromIntegral
+				cx = rng * (fi x - fi w2) / fi w2 + xm :: Double
+				cy = rng * (fi y - fi h2) / fi h2 + ym :: Double
+				(w2, h2) = (width `div` 2, height `div` 2) 
 
 -----------------------------------------
 --QuickCheck Properties
diff --git a/FracState.hs b/FracState.hs
--- a/FracState.hs
+++ b/FracState.hs
@@ -9,8 +9,8 @@
 --These values alter the state in various ways
 iteradd :: Int
 rangemul, cmul :: Double
-rangemul = 1.02
-cmul     = 1.3
+rangemul = 1.013
+cmul     = 1.2
 iteradd  = 100
 
 data Mandstate = Mandstate {
diff --git a/README b/README
--- a/README
+++ b/README
@@ -9,3 +9,5 @@
 p            -    Print a hi-res image of the current location
                   in the working direction
 o			 -    Print current location to console
+
+Can exploit multiple cores - Use hfractal [opts] +RTS -N{cores} to enable this.
diff --git a/hfractal.cabal b/hfractal.cabal
--- a/hfractal.cabal
+++ b/hfractal.cabal
@@ -1,5 +1,5 @@
 name:                hfractal
-version:             0.1.1.0
+version:             0.2.0
 cabal-version:		 >= 1.2
 synopsis:            OpenGL fractal renderer
 category:            Graphics
@@ -13,4 +13,4 @@
     main-is:            Hfractal.hs
     build-depends:      base >=3 && <5, array, gd < 3000.3.0 && >= 3000.2.0, data-accessor >=0.2 && <=0.3, data-accessor-template >=0.2 && <=0.3, OpenGL >= 2.3 && < 2.4, GLUT
     other-Modules:      FracComp, FracState, FracImg, Bindings
-    ghc-options:        -O2
+    ghc-options:        -O2 -threaded