diff --git a/editor/org.processing.editor/META-INF/MANIFEST.MF b/editor/org.processing.editor/META-INF/MANIFEST.MF
index 2ff8a25fd..cb8bd6bd6 100644
--- a/editor/org.processing.editor/META-INF/MANIFEST.MF
+++ b/editor/org.processing.editor/META-INF/MANIFEST.MF
@@ -7,7 +7,8 @@ Bundle-Activator: org.processing.editor.ProcessingEditorPlugin
 Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.ui,
  org.eclipse.jface.text,
- org.eclipse.ui.editors
+ org.eclipse.ui.editors,
+ org.eclipse.core.resources
 Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 Import-Package: org.eclipse.ui.views.contentoutline
 Bundle-ActivationPolicy: lazy
diff --git a/editor/org.processing.editor/bin/org/processing/preferences/PreferenceConstants.class b/editor/org.processing.editor/bin/org/processing/preferences/PreferenceConstants.class
new file mode 100644
index 000000000..84f366997
Binary files /dev/null and b/editor/org.processing.editor/bin/org/processing/preferences/PreferenceConstants.class differ
diff --git a/editor/org.processing.editor/bin/org/processing/preferences/PreferenceInitializer.class b/editor/org.processing.editor/bin/org/processing/preferences/PreferenceInitializer.class
new file mode 100644
index 000000000..774125c25
Binary files /dev/null and b/editor/org.processing.editor/bin/org/processing/preferences/PreferenceInitializer.class differ
diff --git a/editor/org.processing.editor/bin/org/processing/preferences/ProcessingPreferencesPage.class b/editor/org.processing.editor/bin/org/processing/preferences/ProcessingPreferencesPage.class
new file mode 100644
index 000000000..486f6bbba
Binary files /dev/null and b/editor/org.processing.editor/bin/org/processing/preferences/ProcessingPreferencesPage.class differ
diff --git a/editor/org.processing.editor/plugin.xml b/editor/org.processing.editor/plugin.xml
index 7e1d1eb9f..b03cb6b9c 100644
--- a/editor/org.processing.editor/plugin.xml
+++ b/editor/org.processing.editor/plugin.xml
@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <?eclipse version="3.4"?>
 <plugin>
-   <extension
-         point="org.eclipse.ui.editors">
+   <extension point="org.eclipse.ui.editors">
       <editor
             class="org.processing.editor.ProcessingEditor"
             default="true"
@@ -12,26 +11,23 @@
             name="Processing Sketch Editor">
       </editor>
    </extension>
-   <extension
+   <extension point="org.eclipse.core.filebuffers.documentSetup"
          id="ProcessingDocumentSetupParticipant"
-         name="Processing Document Setup Participant"
-         point="org.eclipse.core.filebuffers.documentSetup">
+         name="Processing Document Setup Participant">
       <participant
             class="org.processing.editor.ProcessingDocumentSetupParticipant"
             extensions="pde">
       </participant>
    </extension>
-   <extension
-         point="org.eclipse.core.filebuffers.annotationModelCreation">
+   <extension point="org.eclipse.core.filebuffers.annotationModelCreation">
       <factory
       		extensions="*"
             class="org.eclipse.ui.texteditor.ResourceMarkerAnnotationModelFactory">
       </factory>
    </extension>
-   <extension
+   <extension point="org.eclipse.ui.editorActions"
          id="Processing.EditorSpecificActions"
-         name="Processing Buttons"
-         point="org.eclipse.ui.editorActions">
+         name="Processing Buttons">
       <editorContribution
             id="org.processing.actions.ToolbarButtons"
             targetID="org.processing.editor.ProcessingEditor">
@@ -45,18 +41,33 @@
          </action>
       </editorContribution>
    </extension>
-   <extension
-         point="org.eclipse.ui.preferencePages">
+   <extension point="org.eclipse.ui.preferencePages">
       <page
             class="org.processing.preferences.ProcessingPreferencesPage"
             id="org.processing.preferences.ProcessingPreferencesPage"
             name="Processing">
       </page>
    </extension>
-   <extension
-         point="org.eclipse.core.runtime.preferences">
-      <initializer
-            class="org.processing.preferences.PreferenceInitializer">
+   <extension point="org.eclipse.core.runtime.preferences">
+      <initializer class="org.processing.preferences.PreferenceInitializer">
       </initializer>
    </extension>
+   <extension
+         id="auditmarker"
+         name="Processing Audit Marker"
+         point="org.eclipse.core.resources.markers">
+         <super type="org.eclipse.core.resources.problemmarker"/>
+         <super type="org.eclipse.core.resources.textmarker"/>
+         <persistent value="true"/>
+   </extension>
+   <extension
+         id=""
+         point="org.eclipse.core.resources.builders">
+      <builder
+            hasNature="true">
+         <run
+               class="org.processing.builder.ProcessingSketchAuditor">
+         </run>
+      </builder>
+   </extension>
 </plugin>
diff --git a/editor/org.processing.editor/src/org/processing/preferences/PreferenceConstants.java b/editor/org.processing.editor/src/org/processing/preferences/PreferenceConstants.java
index 61bf7668b..be9b58470 100644
--- a/editor/org.processing.editor/src/org/processing/preferences/PreferenceConstants.java
+++ b/editor/org.processing.editor/src/org/processing/preferences/PreferenceConstants.java
@@ -6,7 +6,8 @@ package org.processing.preferences;
 public class PreferenceConstants {
 
 	// Editor Preferences
-	public static final String PROCESSING_SKETCH = "sketch_path"; // path preference
+	public static final String PROCESSING_SKETCHBOOK = "sketch_path"; // path preference
+	public static final String PROCESSING_LIBRARIES = "library_path"; // path preference
 	public static final String PROCESSING_AUTO_INDENT = "eclipse.editor.auto.indent";
 	
 //	// PROCESSING_PREFERENCES prefix indicates membership in the processing.app preferences class
diff --git a/editor/org.processing.editor/src/org/processing/preferences/ProcessingPreferencesPage.java b/editor/org.processing.editor/src/org/processing/preferences/ProcessingPreferencesPage.java
index 3c9231438..8ad2ade58 100644
--- a/editor/org.processing.editor/src/org/processing/preferences/ProcessingPreferencesPage.java
+++ b/editor/org.processing.editor/src/org/processing/preferences/ProcessingPreferencesPage.java
@@ -19,6 +19,12 @@ import org.processing.editor.ProcessingEditorPlugin;
  * but things could be setup such that these are read
  * from a file, and we could use a customized version of
  * a standard Processing preferences file to store this.
+ * 
+ * Added some validation and warning messages as examples.
+ * If we really want to implement ones of any complexity
+ * there should be an addition of propertyChange() and checkState()
+ * methods. 
+ * See: http://sites.google.com/site/eclipseplugindevelopment/9-preference-pages
  */
 
 public class ProcessingPreferencesPage
@@ -38,8 +44,17 @@ public class ProcessingPreferencesPage
 	 * restore itself.
 	 */
 	public void createFieldEditors() {
-		addField(new DirectoryFieldEditor(PreferenceConstants.PROCESSING_SKETCH, 
-				"Sketchbook Directory:", getFieldEditorParent()));
+		// Sketchbook Directory Item setup
+		DirectoryFieldEditor nextField = new DirectoryFieldEditor(PreferenceConstants.PROCESSING_SKETCHBOOK, "Sketchbook Directory:", getFieldEditorParent());
+		nextField.setEmptyStringAllowed(false);
+		nextField.setErrorMessage("The Sketchbook Directory shouldn't be empty!");
+		addField(nextField);
+		// Library Path item setup
+		nextField = new DirectoryFieldEditor(PreferenceConstants.PROCESSING_LIBRARIES, "Processing Library Path:", getFieldEditorParent());
+		nextField.setEmptyStringAllowed(false);
+		nextField.setErrorMessage("A library path is required to use libraries!");
+		addField(nextField);
+		// Checkbox example setup!
 		addField(
 			new BooleanFieldEditor(
 				PreferenceConstants.PROCESSING_AUTO_INDENT,
@@ -51,5 +66,5 @@ public class ProcessingPreferencesPage
 	 * Initializes the preference page. Nothing to do here, but it has to be subclassed.	  
 	 */
 	public void init(IWorkbench workbench) {}
-	
+		
 }
\ No newline at end of file