diff --git a/CMakeLists.txt b/CMakeLists.txt
index 32c5d41ae..128ebfb6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,6 +48,9 @@ install( FILES
     plasma_export.h
     svg.h
     theme.h
+    DESTINATION ${INCLUDE_INSTALL_DIR}/plasma )
+
+install( FILES
     widgets/icon.h
     widgets/layout.h
     widgets/layoutitem.h
@@ -57,7 +60,7 @@ install( FILES
     widgets/radiobutton.h
     widgets/vboxlayout.h
     widgets/widget.h
-    DESTINATION ${INCLUDE_INSTALL_DIR}/plasma )
+    DESTINATION ${INCLUDE_INSTALL_DIR}/plasma/widgets )
 
 install( FILES
     includes/Applet
diff --git a/abstractrunner.h b/abstractrunner.h
index c861e59ab..0e1e3fa64 100644
--- a/abstractrunner.h
+++ b/abstractrunner.h
@@ -22,7 +22,7 @@
 #include <QtCore/QObject>
 #include <QtCore/QList>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 class KActionCollection;
 class QAction;
diff --git a/applet.cpp b/applet.cpp
index 2671916cc..702f01418 100644
--- a/applet.cpp
+++ b/applet.cpp
@@ -121,18 +121,20 @@ KConfigGroup Applet::globalAppletConfig() const
     return KConfigGroup(d->globalConfig, "General");
 }
 
-bool Applet::loadDataEngine( const QString& name )
+DataEngine* Applet::dataEngine(const QString& name)
 {
-    if ( d->loadedEngines.indexOf( name ) != -1 ) {
-        return true;
+    int index = d->loadedEngines.indexOf(name);
+    if (index != -1) {
+        return DataEngineManager::self()->dataEngine(name);
     }
 
-    if ( DataEngineManager::self()->loadDataEngine( name ) ) {
-        d->loadedEngines.append( name );
-        return true;
+    DataEngine* engine = DataEngineManager::self()->loadDataEngine(name);
+    if (engine) {
+        d->loadedEngines.append(name);
+        return engine;
     }
 
-    return false;
+    return 0;
 }
 
 void Applet::constraintsUpdated()
diff --git a/applet.h b/applet.h
index a17e806fb..9dc99576e 100644
--- a/applet.h
+++ b/applet.h
@@ -26,11 +26,13 @@
 #include <KSharedConfig>
 #include <KGenericFactory>
 
-#include <plasma.h>
-#include <dataengine.h>
+#include <plasma/plasma.h>
 
 namespace Plasma
 {
+
+class DataEngine;
+
 /**
  * @short The base Applet (Plasmoid) class
  *
@@ -92,7 +94,7 @@ class PLASMA_EXPORT Applet : public QObject, public QGraphicsItemGroup
          *
          * @return returns true on success, false on failure
          */
-        bool loadDataEngine( const QString& name );
+        DataEngine* dataEngine(const QString& name);
 
         /**
          * called when any of the geometry constraints have been updated
diff --git a/appletLayout.h b/appletLayout.h
index 2b6602454..d66a8a690 100644
--- a/appletLayout.h
+++ b/appletLayout.h
@@ -4,7 +4,7 @@
 #include <QLayout>
 #include <QSize>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 class QLayoutItem;
 class QRect;
diff --git a/corona.h b/corona.h
index d70030b3c..4fad628c0 100644
--- a/corona.h
+++ b/corona.h
@@ -23,7 +23,7 @@
 
 #include "applet.h"
 #include "plasma.h"
-#include "plasma_export.h"
+#include "plasma/plasma_export.h"
 
 namespace Plasma
 {
diff --git a/dataengine.h b/dataengine.h
index fb916bda9..738517caf 100644
--- a/dataengine.h
+++ b/dataengine.h
@@ -26,7 +26,7 @@
 
 #include <KGenericFactory>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 namespace Plasma
 {
diff --git a/dataenginemanager.h b/dataenginemanager.h
index 296c8e922..c3232eae0 100644
--- a/dataenginemanager.h
+++ b/dataenginemanager.h
@@ -20,7 +20,7 @@
 #define PLASMA_ENGINE_MANAGER_H
 
 #include <QtCore/QHash>
-#include "dataengine.h"
+#include "plasma/dataengine.h"
 
 namespace Plasma
 {
diff --git a/datasource.h b/datasource.h
index 1f29f0830..aaa779505 100644
--- a/datasource.h
+++ b/datasource.h
@@ -22,8 +22,8 @@
 #include <QtCore/QHash>
 #include <QtCore/QObject>
 
-#include <plasma_export.h>
-#include <dataengine.h>
+#include <plasma/plasma_export.h>
+#include <plasma/dataengine.h>
 
 namespace Plasma
 {
diff --git a/plasma.h b/plasma.h
index e72997809..1d9e9eeae 100644
--- a/plasma.h
+++ b/plasma.h
@@ -19,7 +19,7 @@
 #ifndef PLASMA_DEFS_H
 #define PLASMA_DEFS_H
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 /**
  * Namespace for everything in libplasma
diff --git a/svg.h b/svg.h
index 17832802b..d513c9ddd 100644
--- a/svg.h
+++ b/svg.h
@@ -21,7 +21,7 @@
 
 #include <QtCore/QObject>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 class QPainter;
 class QPoint;
diff --git a/theme.h b/theme.h
index 2b92dbdb9..2a01b128e 100644
--- a/theme.h
+++ b/theme.h
@@ -21,7 +21,7 @@
 
 #include <QtCore/QObject>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 namespace Plasma
 {
diff --git a/widgets/checkbox.h b/widgets/checkbox.h
index aef56e87b..1ebf8ee17 100644
--- a/widgets/checkbox.h
+++ b/widgets/checkbox.h
@@ -22,9 +22,9 @@
 #include <QtCore/QObject>
 #include <QtGui/QGraphicsItem>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
-#include <dataengine.h>
+#include <plasma/dataengine.h>
 //TODO
 //Please Document this class
 
diff --git a/widgets/icon.h b/widgets/icon.h
index e83c1de0a..60431259e 100644
--- a/widgets/icon.h
+++ b/widgets/icon.h
@@ -22,9 +22,9 @@
 #include <QtCore/QObject>
 #include <QtGui/QGraphicsTextItem>
 
-#include <widgets/layoutitem.h>
-#include <dataengine.h>
-#include <plasma_export.h>
+#include <plasma/dataengine.h>
+#include <plasma/plasma_export.h>
+#include <plasma/widgets/layoutitem.h>
 
 //TODO
 //Please Document this class
diff --git a/widgets/layout.h b/widgets/layout.h
index 3c140b7e2..ec215807c 100644
--- a/widgets/layout.h
+++ b/widgets/layout.h
@@ -22,9 +22,8 @@
 #include <QtCore/QRectF>
 #include <QtCore/QSizeF>
 
-#include <plasma_export.h>
-
-#include "layoutitem.h"
+#include <plasma/widgets/layoutitem.h>
+#include <plasma/plasma_export.h>
 
 namespace Plasma
 {
diff --git a/widgets/layoutitem.h b/widgets/layoutitem.h
index f66ca7275..6c366d654 100644
--- a/widgets/layoutitem.h
+++ b/widgets/layoutitem.h
@@ -22,7 +22,7 @@
 #include <QtCore/QRectF>
 #include <QtCore/QSizeF>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
 namespace Plasma
 {
diff --git a/widgets/lineedit.h b/widgets/lineedit.h
index 373025c9d..2b7002fe3 100644
--- a/widgets/lineedit.h
+++ b/widgets/lineedit.h
@@ -22,10 +22,10 @@
 #include <QtCore/QObject>
 #include <QtGui/QGraphicsTextItem>
 
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
-#include <dataengine.h>
-#include <widgets/layoutitem.h>
+#include <plasma/dataengine.h>
+#include <plasma/widgets/layoutitem.h>
 
 namespace Plasma
 {
diff --git a/widgets/pushbutton.h b/widgets/pushbutton.h
index 9f447829a..bac0c2153 100644
--- a/widgets/pushbutton.h
+++ b/widgets/pushbutton.h
@@ -23,8 +23,8 @@
 #include <QtGui/QGraphicsTextItem>
 #include <QtGui/QLayoutItem>
 
-#include <dataengine.h>
-#include <plasma_export.h>
+#include <plasma/dataengine.h>
+#include <plasma/plasma_export.h>
 
 //TODO
 //Please Document this class
diff --git a/widgets/radiobutton.h b/widgets/radiobutton.h
index 358f4e404..311887850 100644
--- a/widgets/radiobutton.h
+++ b/widgets/radiobutton.h
@@ -24,9 +24,9 @@
 #include <QtGui/QGraphicsItem>
 
 // KDE includes
-#include <plasma_export.h>
+#include <plasma/plasma_export.h>
 
-#include <dataengine.h>
+#include <plasma/dataengine.h>
 
 namespace Plasma
 {
diff --git a/widgets/vboxlayout.h b/widgets/vboxlayout.h
index 8c91f8ae0..fa35be151 100644
--- a/widgets/vboxlayout.h
+++ b/widgets/vboxlayout.h
@@ -22,9 +22,8 @@
 #include <QtCore/QRectF>
 #include <QtCore/QSizeF>
 
-#include <plasma_export.h>
-
-#include "layout.h"
+#include <plasma/plasma_export.h>
+#include <plasma/widgets/layout.h>
 
 namespace Plasma
 {
diff --git a/widgets/widget.h b/widgets/widget.h
index 7efd05730..52b4f22cf 100644
--- a/widgets/widget.h
+++ b/widgets/widget.h
@@ -25,9 +25,8 @@
 #include <QtCore/QRectF>
 #include <QtCore/QSizeF>
 
-#include <plasma_export.h>
-
-#include "layoutitem.h"
+#include <plasma/widgets/layoutitem.h>
+#include <plasma/plasma_export.h>
 
 namespace Plasma
 {