diff --git a/src/render/software/CanvasPixel.cpp b/src/render/software/CanvasPixel.cpp
index 1b09863..aa11a38 100644
--- a/src/render/software/CanvasPixel.cpp
+++ b/src/render/software/CanvasPixel.cpp
@@ -99,3 +99,8 @@ void CanvasPixel::updateComposite()
     }
     composite = result;
 }
+
+void CanvasPixel::setComposite(const Color &color)
+{
+    composite = color;
+}
diff --git a/src/render/software/CanvasPixel.h b/src/render/software/CanvasPixel.h
index bcbab0a..314e5b0 100644
--- a/src/render/software/CanvasPixel.h
+++ b/src/render/software/CanvasPixel.h
@@ -22,11 +22,13 @@ public:
 
     inline int getFragmentCount() const {return count;}
     inline const Color &getComposite() const {return composite;}
+    inline const CanvasFragment &getFragment(int position) const {return fragments[position];}
     const CanvasFragment *getFrontFragment() const;
 
     void reset();
     void pushFragment(const CanvasFragment &fragment);
     void updateComposite();
+    void setComposite(const Color &color);
 
 private:
     int count;
diff --git a/src/render/software/CanvasPixelShader.cpp b/src/render/software/CanvasPixelShader.cpp
new file mode 100644
index 0000000..6af6479
--- /dev/null
+++ b/src/render/software/CanvasPixelShader.cpp
@@ -0,0 +1,36 @@
+#include "CanvasPixelShader.h"
+
+#include "Color.h"
+#include "SoftwareCanvasRenderer.h"
+#include "CanvasPortion.h"
+#include "CanvasPixel.h"
+#include "CanvasFragment.h"
+#include "Rasterizer.h"
+
+CanvasPixelShader::CanvasPixelShader(const SoftwareCanvasRenderer &renderer, CanvasPortion *portion, int chunk_size, int chunks_x, int chunks_y):
+    renderer(renderer), portion(portion), chunk_size(chunk_size), chunks_x(chunks_x), chunks_y(chunks_y)
+{
+}
+
+int CanvasPixelShader::processParallelUnit(int unit)
+{
+    // Locate the chunk we work on
+    int chunk_x = unit % chunks_x;
+    int chunk_y = unit / chunks_x;
+
+    // Resolve the pixel color
+    int x = chunk_x * chunk_size;
+    int y = chunk_y * chunk_size;
+    const CanvasPixel &pixel = portion->at(x, y);
+    int n = pixel.getFragmentCount();
+    Color composite = COLOR_BLACK;
+    for (int i = 0; i < n; i++)
+    {
+        const CanvasFragment &fragment = pixel.getFragment(i);
+        const Rasterizer &rasterizer = renderer.getRasterizer(fragment.getClient());
+        composite.mask(rasterizer.shadeFragment(fragment));
+    }
+    portion->setColor(x, y, composite);
+
+    return 0;
+}
diff --git a/src/render/software/CanvasPixelShader.h b/src/render/software/CanvasPixelShader.h
new file mode 100644
index 0000000..700bdd9
--- /dev/null
+++ b/src/render/software/CanvasPixelShader.h
@@ -0,0 +1,36 @@
+#ifndef CANVASPIXELSHADER_H
+#define CANVASPIXELSHADER_H
+
+#include "software_global.h"
+
+#include "ParallelWorker.h"
+
+namespace paysages {
+namespace software {
+
+/**
+ * @brief Parallel worker that can work on canvas portion to resolve pixel colors.
+ *
+ * This is used after the rasterization phase to compute pixel colors from the fragments stored in them.
+ *
+ * This worker will be set to work on a given chunk of a canvas portion.
+ */
+class CanvasPixelShader: public ParallelWorker
+{
+public:
+    CanvasPixelShader(const SoftwareCanvasRenderer &renderer, CanvasPortion *portion, int chunk_size, int chunks_x, int chunks_y);
+
+    virtual int processParallelUnit(int unit);
+
+private:
+    const SoftwareCanvasRenderer &renderer;
+    CanvasPortion *portion;
+    int chunk_size;
+    int chunks_x;
+    int chunks_y;
+};
+
+}
+}
+
+#endif // CANVASPIXELSHADER_H
diff --git a/src/render/software/CanvasPortion.cpp b/src/render/software/CanvasPortion.cpp
index 7b1438f..93acae0 100644
--- a/src/render/software/CanvasPortion.cpp
+++ b/src/render/software/CanvasPortion.cpp
@@ -69,3 +69,25 @@ void CanvasPortion::pushFragment(int x, int y, const CanvasFragment &fragment)
         preview->pushPixel(x, y, old_color, pixel.getComposite());
     }
 }
+
+const CanvasPixel &CanvasPortion::at(int x, int y)
+{
+    CHECK_COORDINATES();
+
+    return pixels[y * width + x];
+}
+
+void CanvasPortion::setColor(int x, int y, const Color &color)
+{
+    CHECK_COORDINATES();
+
+    CanvasPixel &pixel = pixels[y * width + x];
+    Color old_color = pixel.getComposite();
+
+    pixel.setComposite(color);
+
+    if (preview)
+    {
+        preview->pushPixel(x, y, old_color, pixel.getComposite());
+    }
+}
diff --git a/src/render/software/CanvasPortion.h b/src/render/software/CanvasPortion.h
index 85be35e..49d88d4 100644
--- a/src/render/software/CanvasPortion.h
+++ b/src/render/software/CanvasPortion.h
@@ -7,7 +7,7 @@ namespace paysages {
 namespace software {
 
 /**
- * @brief Rectangular portion of a Canvas.
+ * Rectangular portion of a Canvas.
  *
  * Contains the pixels of a canvas region (CanvasPixel).
  */
@@ -26,12 +26,26 @@ public:
     void setSize(int width, int height);
 
     /**
-     * @brief Add a fragment to the pixel located at (x, y).
+     * Add a fragment to the pixel located at (x, y).
      *
      * Checking x and y coordinates to be in the canvas portion should be done before this call.
      */
     void pushFragment(int x, int y, const CanvasFragment &fragment);
 
+    /**
+     * Get the CanvasPixel at a given coordinates.
+     *
+     * Checking x and y coordinates to be in the canvas portion should be done before this call.
+     */
+    const CanvasPixel &at(int x, int y);
+
+    /**
+     * Change the final color of the pixel.
+     *
+     * Checking x and y coordinates to be in the canvas portion should be done before this call.
+     */
+    void setColor(int x, int y, const Color &color);
+
 private:
     int width;
     int height;
diff --git a/src/render/software/Rasterizer.cpp b/src/render/software/Rasterizer.cpp
index e2b48b4..009d984 100644
--- a/src/render/software/Rasterizer.cpp
+++ b/src/render/software/Rasterizer.cpp
@@ -136,10 +136,6 @@ void Rasterizer::pushDisplacedQuad(CanvasPortion *canvas, const Vector3 &v1, con
     pushDisplacedTriangle(canvas, v4, v1, v3, ov4, ov1, ov3);
 }
 
-void Rasterizer::rasterizeToCanvas(CanvasPortion *)
-{
-}
-
 void Rasterizer::scanGetDiff(ScanPoint* v1, ScanPoint* v2, ScanPoint* result)
 {
     result->pixel.x = v2->pixel.x - v1->pixel.x;
@@ -316,25 +312,35 @@ void Rasterizer::renderScanLines(CanvasPortion *canvas, RenderScanlines* scanlin
             current.x = x;
             for (cury = starty; cury <= endy; cury++)
             {
-                fy = (double)cury + 0.5;
-                if (fy < down.pixel.y)
+                if (dy == 0)
                 {
-                    fy = down.pixel.y;
+                    // Down and up are the same
+                    current = down;
                 }
-                else if (fy > up.pixel.y)
+                else
                 {
-                    fy = up.pixel.y;
-                }
-                fy = fy - down.pixel.y;
+                    fy = (double)cury + 0.5;
+                    if (fy < down.pixel.y)
+                    {
+                        fy = down.pixel.y;
+                    }
+                    else if (fy > up.pixel.y)
+                    {
+                        fy = up.pixel.y;
+                    }
+                    fy = fy - down.pixel.y;
 
-                current.y = cury;
-                scanInterpolate(renderer->render_camera, &down, &diff, fy / dy, &current);
+                    current.y = cury;
+                    scanInterpolate(renderer->render_camera, &down, &diff, fy / dy, &current);
+                }
 
                 CanvasFragment fragment(current.pixel.z, Vector3(current.location.x, current.location.y, current.location.z), current.client);
 
                 Color frag_color = *color;
                 if (cury == starty || cury == endy)
+                {
                     frag_color.mask(Color(0.0, 0.0, 0.0, 0.3));
+                }
                 fragment.setColor(frag_color);
 
                 canvas->pushFragment(current.x, current.y, fragment);
diff --git a/src/render/software/Rasterizer.h b/src/render/software/Rasterizer.h
index 4e237f1..e364df6 100644
--- a/src/render/software/Rasterizer.h
+++ b/src/render/software/Rasterizer.h
@@ -20,7 +20,8 @@ public:
 
     inline SoftwareRenderer *getRenderer() const {return renderer;}
 
-    virtual void rasterizeToCanvas(CanvasPortion* canvas);
+    virtual void rasterizeToCanvas(CanvasPortion* canvas) = 0;
+    virtual Color shadeFragment(const CanvasFragment &fragment) const = 0;
 
 protected:
     void pushProjectedTriangle(CanvasPortion *canvas, const Vector3 &pixel1, const Vector3 &pixel2, const Vector3 &pixel3, const Vector3 &location1, const Vector3 &location2, const Vector3 &location3);
diff --git a/src/render/software/SkyRasterizer.cpp b/src/render/software/SkyRasterizer.cpp
index 5bb9ff0..dedff67 100644
--- a/src/render/software/SkyRasterizer.cpp
+++ b/src/render/software/SkyRasterizer.cpp
@@ -7,6 +7,7 @@
 #include "AtmosphereResult.h"
 #include "CloudsRenderer.h"
 #include "Rasterizer.h"
+#include "CanvasFragment.h"
 
 #define SPHERE_SIZE 20000.0
 
@@ -15,21 +16,6 @@ SkyRasterizer::SkyRasterizer(SoftwareRenderer* renderer, int client_id):
 {
 }
 
-static Color _postProcessFragment(SoftwareRenderer* renderer, const Vector3 &location, void*)
-{
-    Vector3 camera_location, direction;
-    Color result;
-
-    camera_location = renderer->getCameraLocation(location);
-    direction = location.sub(camera_location);
-
-    /* TODO Don't compute result->color if it's fully covered by clouds */
-    result = renderer->getAtmosphereRenderer()->getSkyColor(direction.normalize()).final;
-    result = renderer->getCloudsRenderer()->getColor(camera_location, camera_location.add(direction.scale(10.0)), result);
-
-    return result;
-}
-
 void SkyRasterizer::rasterizeToCanvas(CanvasPortion* canvas)
 {
     int res_i, res_j;
@@ -84,3 +70,19 @@ void SkyRasterizer::rasterizeToCanvas(CanvasPortion* canvas)
         }
     }
 }
+
+Color SkyRasterizer::shadeFragment(const CanvasFragment &fragment) const
+{
+    Vector3 location = fragment.getLocation();
+    Vector3 camera_location, direction;
+    Color result;
+
+    camera_location = renderer->getCameraLocation(location);
+    direction = location.sub(camera_location);
+
+    /* TODO Don't compute result->color if it's fully covered by clouds */
+    result = renderer->getAtmosphereRenderer()->getSkyColor(direction.normalize()).final;
+    result = renderer->getCloudsRenderer()->getColor(camera_location, camera_location.add(direction.scale(10.0)), result);
+
+    return result;
+}
diff --git a/src/render/software/SkyRasterizer.h b/src/render/software/SkyRasterizer.h
index 0e44b76..89436b9 100644
--- a/src/render/software/SkyRasterizer.h
+++ b/src/render/software/SkyRasterizer.h
@@ -14,6 +14,7 @@ public:
     SkyRasterizer(SoftwareRenderer* renderer, int client_id);
 
     virtual void rasterizeToCanvas(CanvasPortion* canvas);
+    virtual Color shadeFragment(const CanvasFragment &fragment) const;
 };
 
 }
diff --git a/src/render/software/SoftwareCanvasRenderer.cpp b/src/render/software/SoftwareCanvasRenderer.cpp
index 0252be6..4007e32 100644
--- a/src/render/software/SoftwareCanvasRenderer.cpp
+++ b/src/render/software/SoftwareCanvasRenderer.cpp
@@ -7,6 +7,9 @@
 #include "WaterRasterizer.h"
 #include "SkyRasterizer.h"
 #include "CameraDefinition.h"
+#include "ParallelWork.h"
+#include "CanvasPortion.h"
+#include "CanvasPixelShader.h"
 
 SoftwareCanvasRenderer::SoftwareCanvasRenderer()
 {
@@ -58,6 +61,11 @@ const std::vector<Rasterizer *> &SoftwareCanvasRenderer::getRasterizers() const
     return rasterizers;
 }
 
+const Rasterizer &SoftwareCanvasRenderer::getRasterizer(int client_id) const
+{
+    return *(getRasterizers()[client_id]);
+}
+
 void SoftwareCanvasRenderer::rasterize(CanvasPortion *portion, bool threaded)
 {
     for (auto &rasterizer:getRasterizers())
@@ -68,5 +76,14 @@ void SoftwareCanvasRenderer::rasterize(CanvasPortion *portion, bool threaded)
 
 void SoftwareCanvasRenderer::postProcess(CanvasPortion *portion, bool threaded)
 {
-    // TODO
+    // Subdivide in chunks
+    int chunk_size = 32;
+    int chunks_x = portion->getWidth() / chunk_size + 1;
+    int chunks_y = portion->getHeight() / chunk_size + 1;
+    int units = chunks_x * chunks_y;
+
+    // Render chunks in parallel
+    CanvasPixelShader shader(*this, portion, chunk_size, chunks_x, chunks_y);
+    ParallelWork work(&shader, units);
+    work.perform();
 }
diff --git a/src/render/software/SoftwareCanvasRenderer.h b/src/render/software/SoftwareCanvasRenderer.h
index 3f51569..e18f150 100644
--- a/src/render/software/SoftwareCanvasRenderer.h
+++ b/src/render/software/SoftwareCanvasRenderer.h
@@ -36,11 +36,16 @@ public:
      */
     void render();
 
-    /*!
-     * \brief Get the list of objects that can be rasterized to polygons on a canvas.
+    /**
+     * @brief Get the list of objects that can be rasterized to polygons on a canvas.
      */
     virtual const std::vector<Rasterizer*> &getRasterizers() const;
 
+    /**
+     * Get a rasterizer by its client id.
+     */
+    const Rasterizer &getRasterizer(int client_id) const;
+
 protected:
     /**
      * @brief Rasterize the scenery into a canvas portion.
diff --git a/src/render/software/TerrainRasterizer.cpp b/src/render/software/TerrainRasterizer.cpp
index a723137..b677b81 100644
--- a/src/render/software/TerrainRasterizer.cpp
+++ b/src/render/software/TerrainRasterizer.cpp
@@ -9,6 +9,7 @@
 #include "Scenery.h"
 #include "ParallelQueue.h"
 #include "CanvasPortion.h"
+#include "CanvasFragment.h"
 
 TerrainRasterizer::TerrainRasterizer(SoftwareRenderer* renderer, int client_id):
     Rasterizer(renderer, client_id, Color(0.5, 0.3, 0.3))
@@ -20,12 +21,6 @@ static inline Vector3 _getPoint(SoftwareRenderer* renderer, double x, double z)
     return Vector3(x, renderer->getTerrainRenderer()->getHeight(x, z, 1), z);
 }
 
-static Color _postProcessFragment(SoftwareRenderer* renderer, const Vector3 &point, void*)
-{
-    double precision = renderer->getPrecision(_getPoint(renderer, point.x, point.z));
-    return renderer->getTerrainRenderer()->getFinalColor(point, precision);
-}
-
 void TerrainRasterizer::tessellateChunk(CanvasPortion* canvas, TerrainChunkInfo* chunk, int detail)
 {
     if (detail < 1)
@@ -245,3 +240,10 @@ void TerrainRasterizer::rasterizeToCanvas(CanvasPortion *canvas)
 
     queue->wait();
 }
+
+Color TerrainRasterizer::shadeFragment(const CanvasFragment &fragment) const
+{
+    Vector3 point = fragment.getLocation();
+    double precision = renderer->getPrecision(_getPoint(renderer, point.x, point.z));
+    return renderer->getTerrainRenderer()->getFinalColor(point, precision);
+}
diff --git a/src/render/software/TerrainRasterizer.h b/src/render/software/TerrainRasterizer.h
index af8b020..0e6537f 100644
--- a/src/render/software/TerrainRasterizer.h
+++ b/src/render/software/TerrainRasterizer.h
@@ -51,6 +51,7 @@ public:
     virtual void rasterize();
 
     virtual void rasterizeToCanvas(CanvasPortion* canvas);
+    virtual Color shadeFragment(const CanvasFragment &fragment) const;
 
 private:
     ParallelQueue* queue;
diff --git a/src/render/software/WaterRasterizer.cpp b/src/render/software/WaterRasterizer.cpp
index 6f99ac4..92face3 100644
--- a/src/render/software/WaterRasterizer.cpp
+++ b/src/render/software/WaterRasterizer.cpp
@@ -3,17 +3,13 @@
 #include "SoftwareRenderer.h"
 #include "WaterRenderer.h"
 #include "ParallelQueue.h"
+#include "CanvasFragment.h"
 
 WaterRasterizer::WaterRasterizer(SoftwareRenderer* renderer, int client_id):
     Rasterizer(renderer, client_id, Color(0.1, 0.3, 0.6))
 {
 }
 
-static Color _postProcessFragment(SoftwareRenderer* renderer, const Vector3 &location, void*)
-{
-    return renderer->getWaterRenderer()->getResult(location.x, location.z).final;
-}
-
 static inline Vector3 _getFirstPassVertex(SoftwareRenderer* renderer, double x, double z)
 {
     Vector3 result;
@@ -84,3 +80,9 @@ void WaterRasterizer::rasterizeToCanvas(CanvasPortion *canvas)
         radius_ext += chunk_size;
     }
 }
+
+Color WaterRasterizer::shadeFragment(const CanvasFragment &fragment) const
+{
+    Vector3 location = fragment.getLocation();
+    return renderer->getWaterRenderer()->getResult(location.x, location.z).final;
+}
diff --git a/src/render/software/WaterRasterizer.h b/src/render/software/WaterRasterizer.h
index e8cda24..902d179 100644
--- a/src/render/software/WaterRasterizer.h
+++ b/src/render/software/WaterRasterizer.h
@@ -16,6 +16,7 @@ public:
     void rasterizeQuad(CanvasPortion* canvas, double x, double z, double size);
 
     virtual void rasterizeToCanvas(CanvasPortion* canvas);
+    virtual Color shadeFragment(const CanvasFragment &fragment) const;
 };
 
 }
diff --git a/src/render/software/software.pro b/src/render/software/software.pro
index 8f6ba50..4543bf3 100644
--- a/src/render/software/software.pro
+++ b/src/render/software/software.pro
@@ -45,7 +45,8 @@ SOURCES += SoftwareRenderer.cpp \
     Rasterizer.cpp \
     CanvasLiveClient.cpp \
     CanvasPreview.cpp \
-    RenderConfig.cpp
+    RenderConfig.cpp \
+    CanvasPixelShader.cpp
 
 HEADERS += SoftwareRenderer.h\
         software_global.h \
@@ -80,7 +81,8 @@ HEADERS += SoftwareRenderer.h\
     Rasterizer.h \
     CanvasLiveClient.h \
     CanvasPreview.h \
-    RenderConfig.h
+    RenderConfig.h \
+    CanvasPixelShader.h
 
 unix:!symbian {
     maemo5 {
diff --git a/src/render/software/software_global.h b/src/render/software/software_global.h
index fc6a3fd..0aa9636 100644
--- a/src/render/software/software_global.h
+++ b/src/render/software/software_global.h
@@ -53,6 +53,7 @@ namespace software {
     class CanvasFragment;
     class CanvasLiveClient;
     class CanvasPreview;
+    class CanvasPixelShader;
 }
 }
 
diff --git a/src/system/ParallelWork.cpp b/src/system/ParallelWork.cpp
index acd94f7..9fb57ef 100644
--- a/src/system/ParallelWork.cpp
+++ b/src/system/ParallelWork.cpp
@@ -2,37 +2,72 @@
 
 #include "Thread.h"
 #include "System.h"
+#include "ParallelWorker.h"
 #include <cassert>
 
+/**
+ * Compatibility class for code that uses ParallelUnitFunction.
+ */
+class ParallelWorkerCompat:public ParallelWorker
+{
+public:
+    ParallelWorkerCompat(ParallelWork *work, ParallelWork::ParallelUnitFunction func, void* data):
+        ParallelWorker(), work(work), func(func), data(data)
+    {
+    }
+
+    virtual int processParallelUnit(int unit)
+    {
+        return func(work, unit, data);
+    }
+
+private:
+    ParallelWork* work;
+    ParallelWork::ParallelUnitFunction func;
+    void* data;
+};
+
+ParallelWork::ParallelWork(ParallelWorker *worker, int units)
+{
+    this->units = units;
+    this->running = 0;
+    this->worker = worker;
+    this->worker_compat = false;
+}
+
 ParallelWork::ParallelWork(ParallelUnitFunction func, int units, void* data)
 {
     this->units = units;
     this->running = 0;
-    this->unit_function = func;
-    this->data = data;
+    this->worker = new ParallelWorkerCompat(this, func, data);
+    this->worker_compat = true;
 }
 
 ParallelWork::~ParallelWork()
 {
     assert(not running);
+    if (worker_compat)
+    {
+        delete worker;
+    }
 }
 
-static void* _workerThreadCallback(ParallelWork::ParallelWorker* worker)
+static void* _workerThreadCallback(ParallelWork::ParallelWorkerThread* thread)
 {
-    worker->result = worker->work->unit_function(worker->work, worker->unit, worker->work->data);
-    worker->status = ParallelWork::PARALLEL_WORKER_STATUS_DONE;
+    thread->result = thread->worker->processParallelUnit(thread->unit);
+    thread->status = ParallelWork::PARALLEL_WORKER_STATUS_DONE;
     return NULL;
 }
 
-static int _runNextWorker(ParallelWork::ParallelWorker workers[], int worker_count, int unit)
+static int _runNextWorker(ParallelWork::ParallelWorkerThread threads[], int thread_count, int unit)
 {
     int i;
 
     while (1)
     {
-        for (i = 0; i < worker_count; i++)
+        for (i = 0; i < thread_count; i++)
         {
-            ParallelWork::ParallelWorker* worker = workers + i;
+            ParallelWork::ParallelWorkerThread* worker = threads + i;
             if (worker->status == ParallelWork::PARALLEL_WORKER_STATUS_VOID)
             {
                 worker->status = ParallelWork::PARALLEL_WORKER_STATUS_RUNNING;
@@ -62,47 +97,47 @@ static int _runNextWorker(ParallelWork::ParallelWorker workers[], int worker_cou
     }
 }
 
-int ParallelWork::perform(int nbworkers)
+int ParallelWork::perform(int thread_count)
 {
     int i, done, result;
     assert(not running);
 
     result = 0;
 
-    if (nbworkers <= 0)
+    if (thread_count <= 0)
     {
-        nbworkers = System::getCoreCount();
+        thread_count = System::getCoreCount();
     }
-    if (nbworkers > PARALLEL_MAX_THREADS)
+    if (thread_count > PARALLEL_MAX_THREADS)
     {
-        nbworkers = PARALLEL_MAX_THREADS;
+        thread_count = PARALLEL_MAX_THREADS;
     }
     running = 1;
 
     /* Init workers */
-    for (i = 0; i < nbworkers; i++)
+    for (i = 0; i < thread_count; i++)
     {
-        workers[i].status = PARALLEL_WORKER_STATUS_VOID;
-        workers[i].work = this;
+        threads[i].status = PARALLEL_WORKER_STATUS_VOID;
+        threads[i].worker = worker;
     }
 
     /* Perform run */
     for (done = 0; done < units; done++)
     {
-        if (_runNextWorker(workers, nbworkers, done))
+        if (_runNextWorker(threads, thread_count, done))
         {
             result++;
         }
     }
 
     /* Wait and clean up workers */
-    for (i = 0; i < nbworkers; i++)
+    for (i = 0; i < thread_count; i++)
     {
-        if (workers[i].status != PARALLEL_WORKER_STATUS_VOID)
+        if (threads[i].status != PARALLEL_WORKER_STATUS_VOID)
         {
-            workers[i].thread->join();
-            delete workers[i].thread;
-            if (workers[i].result)
+            threads[i].thread->join();
+            delete threads[i].thread;
+            if (threads[i].result)
             {
                 result++;
             }
diff --git a/src/system/ParallelWork.h b/src/system/ParallelWork.h
index 528ce31..9f4b756 100644
--- a/src/system/ParallelWork.h
+++ b/src/system/ParallelWork.h
@@ -23,22 +23,24 @@ public:
     typedef struct
     {
         Thread* thread;
-        ParallelWork* work;
+        ParallelWorker* worker;
         ParallelWorkerStatus status;
         int unit;
         int result;
-    } ParallelWorker;
+    } ParallelWorkerThread;
 
 public:
     /**
      * Create a parallel work handler.
      *
-     * This will spawn an optimal number of threads to process a given number of work units.
+     * This will spawn a number of threads.
+     */
+    ParallelWork(ParallelWorker *worker, int units);
+
+    /**
+     * Create a parallel work handler.
      *
-     * @param func The callback that will be called from threads to process one unit.
-     * @param units Number of units to handle.
-     * @param data Custom data that will be passed to the callback.
-     * @return The newly allocated handler.
+     * This is a compatibility constructor for older code, use the constructor with ParallelWorker instead.
      */
     ParallelWork(ParallelUnitFunction func, int units, void* data);
 
@@ -52,15 +54,15 @@ public:
     /**
      * Start working on the units.
      *
-     * @param workers Number of threads to spaws, -1 for an optimal number.
+     * @param threads Number of threads to spaws, -1 for an optimal number.
      */
-    int perform(int workers=-1);
+    int perform(int thread_count=-1);
 
     int units;
     int running;
-    ParallelUnitFunction unit_function;
-    ParallelWorker workers[PARALLEL_MAX_THREADS];
-    void* data;
+    ParallelWorker *worker;
+    bool worker_compat;
+    ParallelWorkerThread threads[PARALLEL_MAX_THREADS];
 };
 
 }
diff --git a/src/system/ParallelWorker.cpp b/src/system/ParallelWorker.cpp
new file mode 100644
index 0000000..0e64c57
--- /dev/null
+++ b/src/system/ParallelWorker.cpp
@@ -0,0 +1,9 @@
+#include "ParallelWorker.h"
+
+ParallelWorker::ParallelWorker()
+{
+}
+
+ParallelWorker::~ParallelWorker()
+{
+}
diff --git a/src/system/ParallelWorker.h b/src/system/ParallelWorker.h
new file mode 100644
index 0000000..b77f08c
--- /dev/null
+++ b/src/system/ParallelWorker.h
@@ -0,0 +1,29 @@
+#ifndef PARALLELWORKER_H
+#define PARALLELWORKER_H
+
+#include "system_global.h"
+
+namespace paysages {
+namespace system {
+
+/**
+ * @brief Worker that can be used by the ParallelWork object to perform tasks in several threads.
+ */
+class SYSTEMSHARED_EXPORT ParallelWorker
+{
+public:
+    ParallelWorker();
+    virtual ~ParallelWorker();
+
+    /**
+     * Abstract method to reimplement to process a work unit.
+     *
+     * This method will be called from any thread in the thread pool used by the ParallelWork.
+     */
+    virtual int processParallelUnit(int unit) = 0;
+};
+
+}
+}
+
+#endif // PARALLELWORKER_H
diff --git a/src/system/system.pro b/src/system/system.pro
index 5de52fa..73a8234 100644
--- a/src/system/system.pro
+++ b/src/system/system.pro
@@ -25,7 +25,8 @@ SOURCES += \
     CacheFile.cpp \
     PictureWriter.cpp \
     Logs.cpp \
-    ParallelPool.cpp
+    ParallelPool.cpp \
+    ParallelWorker.cpp
 
 HEADERS += \
     system_global.h \
@@ -40,7 +41,8 @@ HEADERS += \
     CacheFile.h \
     PictureWriter.h \
     Logs.h \
-    ParallelPool.h
+    ParallelPool.h \
+    ParallelWorker.h
 
 unix:!symbian {
     maemo5 {
diff --git a/src/system/system_global.h b/src/system/system_global.h
index 52e9755..c490cdf 100644
--- a/src/system/system_global.h
+++ b/src/system/system_global.h
@@ -18,6 +18,7 @@ namespace system {
     class ParallelQueue;
     class ParallelWork;
     class ParallelPool;
+    class ParallelWorker;
     class Thread;
     class Mutex;
 }