diff --git a/src/org/aavso/tools/vstar/ui/dialog/TextAreaTabs.java b/src/org/aavso/tools/vstar/ui/dialog/TextAreaTabs.java
index abfe0ca8..d7cf2f3d 100644
--- a/src/org/aavso/tools/vstar/ui/dialog/TextAreaTabs.java
+++ b/src/org/aavso/tools/vstar/ui/dialog/TextAreaTabs.java
@@ -33,130 +33,125 @@
  */
 public class TextAreaTabs implements ITextComponent<String> {
 
-	private boolean canBeEmpty;
-	private boolean readOnly;
-
-	private List<JTextArea> textAreas;
-
-	private JTabbedPane tabs;
-
-	/**
-	 * Constructor.
-	 * 
-	 * @param names
-	 *            The list of tab names.
-	 * @param initialValues
-	 *            The list of initial text area values.
-	 * @param rows
-	 *            The number of rows in these text areas; 0 means don't set;
-	 *            applied to all text areas.
-	 * @param cols
-	 *            The number of rows in these text areas; 0 means don't set;
-	 *            applied to all text areas.
-	 * @param readOnly
-	 *            Are all these areas read-only?
-	 * @param canBeEmpty
-	 *            Can any of these areas be empty? (all or none)
-	 */
-	public TextAreaTabs(List<String> names, List<String> initialValues,
-			int rows, int cols, boolean readOnly, boolean canBeEmpty) {
-		assert names.size() == initialValues.size();
-
-		this.readOnly = readOnly;
-		this.canBeEmpty = canBeEmpty;
-		this.textAreas = new ArrayList<JTextArea>();
-
-		List<NamedComponent> namedComponents = new ArrayList<NamedComponent>();
-
-		for (int i = 0; i < names.size(); i++) {
-			JTextArea textArea = new JTextArea(
-					initialValues.get(i) == null ? "" : initialValues.get(i));
-
-			textAreas.add(textArea);
-
-			// textArea.setBorder(BorderFactory.createTitledBorder(names.get(i)));
-			if (!isReadOnly()) {
-				textArea.setToolTipText("Enter " + names.get(i));
-			}
-
-			namedComponents.add(new NamedComponent(names.get(i),
-					new JScrollPane(textArea)));
-		}
-
-		for (JTextArea textArea : textAreas) {
-			if (rows != 0) {
-				textArea.setRows(rows);
-			}
-
-			if (cols != 0) {
-				textArea.setColumns(cols);
-			}
-		}
-
-		tabs = PluginComponentFactory.createTabs(namedComponents);
-	}
-
-	@Override
-	public String getName() {
-		return null;
-	}
-
-	@Override
-	public boolean canBeEmpty() {
-		return canBeEmpty;
-	}
-
-	@Override
-	public boolean isReadOnly() {
-		return readOnly;
-	}
-
-	@Override
-	public String getValue() {
-		StringBuffer value = new StringBuffer();
-
-		for (JTextArea textArea : textAreas) {
-			value.append(textArea.getText());
-			value.append("\n");
-		}
-
-		return value.toString();
-	}
-
-	@Override
-	public String getStringValue() {
-		StringBuffer buf = new StringBuffer();
-
-		for (JTextArea textArea : textAreas) {
-			buf.append(textArea.getText());
-			buf.append("\n");
-		}
-
-		return buf.toString();
-	}
-
-	@Override
-	public void setEditable(boolean state) {
-		readOnly = !state;
-
-	}
-
-	@Override
-	public void setValue(String value) {
-		if ("".equals(value)) {
-			for (JTextArea textArea : textAreas) {
-				textArea.setText("");
-			}
-		} else {
-			String[] values = value.split("\\<sentinel\\>");
-			for (int i = 0; i < values.length; i++) {
-				textAreas.get(i).setText(values[i]);
-			}
-		}
-	}
-
-	@Override
-	public JComponent getUIComponent() {
-		return tabs;
-	}
+    private boolean canBeEmpty;
+    private boolean readOnly;
+    private String tabTextseparator;
+
+    private List<JTextArea> textAreas;
+
+    private JTabbedPane tabs;
+
+    /**
+     * Constructor.
+     * 
+     * @param names            The list of tab names.
+     * @param initialValues    The list of initial text area values.
+     * @param rows             The number of rows in these text areas; 0 means don't
+     *                         set; applied to all text areas.
+     * @param cols             The number of rows in these text areas; 0 means don't
+     *                         set; applied to all text areas.
+     * @param readOnly         Are all these areas read-only?
+     * @param canBeEmpty       Can any of these areas be empty? (all or none)
+     * @param tabTextseparator The text value separator for each tabbed text pane.
+     */
+    public TextAreaTabs(List<String> names, List<String> initialValues, int rows, int cols, boolean readOnly,
+            boolean canBeEmpty, String tabTextseparator) {
+        assert names.size() == initialValues.size();
+
+        this.readOnly = readOnly;
+        this.canBeEmpty = canBeEmpty;
+        this.tabTextseparator = tabTextseparator;
+        this.textAreas = new ArrayList<JTextArea>();
+
+        List<NamedComponent> namedComponents = new ArrayList<NamedComponent>();
+
+        for (int i = 0; i < names.size(); i++) {
+            JTextArea textArea = new JTextArea(initialValues.get(i) == null ? "" : initialValues.get(i));
+
+            textAreas.add(textArea);
+
+            // textArea.setBorder(BorderFactory.createTitledBorder(names.get(i)));
+            if (!isReadOnly()) {
+                textArea.setToolTipText("Enter " + names.get(i));
+            }
+
+            namedComponents.add(new NamedComponent(names.get(i), new JScrollPane(textArea)));
+        }
+
+        for (JTextArea textArea : textAreas) {
+            if (rows != 0) {
+                textArea.setRows(rows);
+            }
+
+            if (cols != 0) {
+                textArea.setColumns(cols);
+            }
+        }
+
+        tabs = PluginComponentFactory.createTabs(namedComponents);
+    }
+
+    @Override
+    public String getName() {
+        return null;
+    }
+
+    @Override
+    public boolean canBeEmpty() {
+        return canBeEmpty;
+    }
+
+    @Override
+    public boolean isReadOnly() {
+        return readOnly;
+    }
+
+    @Override
+    public String getValue() {
+        StringBuffer value = new StringBuffer();
+
+        for (JTextArea textArea : textAreas) {
+            value.append(textArea.getText());
+            value.append("\n");
+        }
+
+        return value.toString();
+    }
+
+    @Override
+    public String getStringValue() {
+        StringBuffer buf = new StringBuffer();
+
+        for (JTextArea textArea : textAreas) {
+            buf.append(textArea.getText());
+            buf.append("\n");
+        }
+
+        return buf.toString();
+    }
+
+    @Override
+    public void setEditable(boolean state) {
+        readOnly = !state;
+
+    }
+
+    @Override
+    public void setValue(String value) {
+        if ("".equals(value)) {
+            for (JTextArea textArea : textAreas) {
+                textArea.setText("");
+            }
+        } else {
+            String[] values = value.split(tabTextseparator);
+            for (int i = 0; i < values.length; i++) {
+                textAreas.get(i).setText(values[i]);
+            }
+        }
+    }
+
+    @Override
+    public JComponent getUIComponent() {
+        return tabs;
+    }
 }
diff --git a/src/org/aavso/tools/vstar/ui/dialog/prefs/PreferencesDialog.java b/src/org/aavso/tools/vstar/ui/dialog/prefs/PreferencesDialog.java
index 09d56b6e..1a26bf88 100644
--- a/src/org/aavso/tools/vstar/ui/dialog/prefs/PreferencesDialog.java
+++ b/src/org/aavso/tools/vstar/ui/dialog/prefs/PreferencesDialog.java
@@ -40,6 +40,7 @@ public class PreferencesDialog extends AbstractOkCancelDialog {
 	private StarGroupManagementPane starGroupManagementPane;
 	private PluginSettingsPane pluginSettingsPane;
 	private LocaleSelectionPane localeSelectionPane;
+	private VeLaSettingsPane veLaSettingsPane;
 	
 	/**
 	 * Constructor.
@@ -86,6 +87,9 @@ private JTabbedPane createTabs() {
 		localeSelectionPane = new LocaleSelectionPane();
 		tabs.addTab("Locale", localeSelectionPane);
 		
+		veLaSettingsPane = new VeLaSettingsPane();
+		tabs.addTab("VeLa", veLaSettingsPane);
+		
 		return tabs;
 	}
 
@@ -107,6 +111,7 @@ protected void okAction() {
 		starGroupManagementPane.update();
 		pluginSettingsPane.update();
 		localeSelectionPane.update();
+		veLaSettingsPane.update();
 		
 		this.setVisible(false);
 	}
@@ -122,6 +127,7 @@ protected void reset() {
 		starGroupManagementPane.reset();
 		pluginSettingsPane.reset();
 		localeSelectionPane.reset();
+		veLaSettingsPane.reset();
 	}
 
 	/**
diff --git a/src/org/aavso/tools/vstar/ui/dialog/prefs/VeLaSettingsPane.java b/src/org/aavso/tools/vstar/ui/dialog/prefs/VeLaSettingsPane.java
new file mode 100644
index 00000000..7841b362
--- /dev/null
+++ b/src/org/aavso/tools/vstar/ui/dialog/prefs/VeLaSettingsPane.java
@@ -0,0 +1,168 @@
+/**
+ * VStar: a statistical analysis tool for variable star data.
+ * Copyright (C) 2009  AAVSO (http://www.aavso.org/)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
+ */
+package org.aavso.tools.vstar.ui.dialog.prefs;
+
+import java.awt.BorderLayout;
+import java.awt.Dimension;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.io.File;
+
+import javax.swing.BorderFactory;
+import javax.swing.Box;
+import javax.swing.BoxLayout;
+import javax.swing.JButton;
+import javax.swing.JCheckBox;
+import javax.swing.JFileChooser;
+import javax.swing.JPanel;
+import javax.swing.JTextArea;
+
+import org.aavso.tools.vstar.ui.mediator.DocumentManager;
+import org.aavso.tools.vstar.util.locale.LocaleProps;
+import org.aavso.tools.vstar.vela.VeLaPrefs;
+
+/**
+ * VeLa Preferences pane
+ */
+@SuppressWarnings("serial")
+public class VeLaSettingsPane extends JPanel implements IPreferenceComponent {
+
+    private JFileChooser veLaCodeDirectoryChooser;
+    private JTextArea veLaCodeDirectoriesField;
+
+    private JCheckBox veLaDiagnosticCheckbox;
+
+    public VeLaSettingsPane() {
+        JPanel veLaSettingsPanel = new JPanel();
+        veLaSettingsPanel.setLayout(new BoxLayout(veLaSettingsPanel, BoxLayout.PAGE_AXIS));
+        veLaSettingsPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
+
+        // VeLa code directories
+        JPanel veLaCodeDirPanel = new JPanel();
+        veLaCodeDirPanel.setLayout(new BoxLayout(veLaCodeDirPanel, BoxLayout.LINE_AXIS));
+        veLaCodeDirPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
+
+        veLaCodeDirectoriesField = new JTextArea(VeLaPrefs.getCodeDirs());
+        veLaCodeDirectoriesField.setEditable(false);
+        veLaCodeDirectoriesField.setToolTipText("VeLa code directories");
+        veLaCodeDirectoriesField.setBorder(BorderFactory.createTitledBorder("Directories"));
+
+        veLaCodeDirPanel.add(veLaCodeDirectoriesField);
+
+        veLaCodeDirectoryChooser = new JFileChooser();
+        veLaCodeDirectoryChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
+
+        JButton addVeLaCodeDirButton = new JButton("Add VeLa Code Directory");
+        addVeLaCodeDirButton.addActionListener(e -> requestDirToAdd());
+
+        veLaCodeDirPanel.add(addVeLaCodeDirButton);
+
+        veLaSettingsPanel.add(veLaCodeDirPanel);
+
+        veLaSettingsPanel.add(Box.createRigidArea(new Dimension(10, 10)));
+
+        // VeLa dialog diagnostic mode
+        JPanel veLaCheckboxPanel = new JPanel();
+        veLaCheckboxPanel.setLayout(new BoxLayout(veLaCheckboxPanel, BoxLayout.LINE_AXIS));
+        veLaCheckboxPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
+
+        veLaDiagnosticCheckbox = new JCheckBox("Additional diagnostic tabs in VeLa dialog?");
+        veLaDiagnosticCheckbox.setSelected(VeLaPrefs.getDiagnosticMode());
+        veLaDiagnosticCheckbox.setToolTipText("Tabs for Abstract Syntax Trees in DOT and LISP form");
+
+        veLaCheckboxPanel.add(veLaDiagnosticCheckbox);
+        veLaSettingsPanel.add(veLaCheckboxPanel);
+
+        veLaSettingsPanel.add(Box.createRigidArea(new Dimension(10, 10)));
+
+        // Add a local context button pane.
+        veLaSettingsPanel.add(createButtonPane());
+
+        add(veLaSettingsPanel);
+    }
+
+    protected JPanel createButtonPane() {
+        JPanel panel = new JPanel(new BorderLayout());
+
+        JButton setDefaultsButton = new JButton("Set Defaults");
+        setDefaultsButton.addActionListener(createSetDefaultsButtonActionListener());
+        panel.add(setDefaultsButton, BorderLayout.LINE_START);
+
+        JButton applyButton = new JButton(LocaleProps.get("APPLY_BUTTON"));
+        applyButton.addActionListener(createApplyButtonActionListener());
+        panel.add(applyButton, BorderLayout.LINE_END);
+
+        return panel;
+    }
+
+    @Override
+    public void update() {
+        VeLaPrefs.setCodeDirs(veLaCodeDirectoriesField.getText());
+        VeLaPrefs.setDiagnosticMode(veLaDiagnosticCheckbox.isSelected());
+    }
+
+    /**
+     * Prepare this pane for use by resetting whatever needs to be, in particular,
+     * updating widgets with current preferences.
+     */
+    @Override
+    public void reset() {
+        veLaCodeDirectoriesField.setText(VeLaPrefs.getCodeDirs());
+        veLaDiagnosticCheckbox.setSelected(VeLaPrefs.getDiagnosticMode());
+    }
+
+    // Set defaults action button listener creator.
+    private ActionListener createSetDefaultsButtonActionListener() {
+        return new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                veLaDiagnosticCheckbox.setSelected(Boolean.parseBoolean(VeLaPrefs.DEFAULT_DIAGNOSTIC_MODE_STR));
+                veLaCodeDirectoriesField.setText(VeLaPrefs.DEFAULT_CODE_DIR_STR);
+            }
+        };
+    }
+
+    // Set apply button listener creator.
+    private ActionListener createApplyButtonActionListener() {
+        return new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                update();
+            }
+        };
+    }
+
+    /**
+     * Open file chooser to ask for a code directory to add.
+     * 
+     * @return An optional directory
+     */
+    private void requestDirToAdd() {
+        int retVal = veLaCodeDirectoryChooser.showOpenDialog(DocumentManager.findActiveWindow());
+
+        if (retVal == JFileChooser.APPROVE_OPTION) {
+            File dir = veLaCodeDirectoryChooser.getSelectedFile();
+
+            String dirStr = veLaCodeDirectoriesField.getText();
+            if (!dirStr.isEmpty()) {
+                // TODO: perhaps we really want a JList instead with dirList as model
+                dirStr += "\n";
+            }
+            dirStr += dir.getAbsolutePath();
+            veLaCodeDirectoriesField.setText(dirStr);
+        }
+    }
+}
diff --git a/src/org/aavso/tools/vstar/ui/vela/VeLaDialog.java b/src/org/aavso/tools/vstar/ui/vela/VeLaDialog.java
index 4395f558..7472a65f 100644
--- a/src/org/aavso/tools/vstar/ui/vela/VeLaDialog.java
+++ b/src/org/aavso/tools/vstar/ui/vela/VeLaDialog.java
@@ -25,18 +25,18 @@
 import java.io.FileOutputStream;
 import java.io.PrintStream;
 import java.util.Arrays;
-import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 import javax.swing.BoxLayout;
 import javax.swing.JButton;
-import javax.swing.JCheckBox;
 import javax.swing.JPanel;
 import javax.swing.JTextArea;
 
 import org.aavso.tools.vstar.ui.dialog.ITextComponent;
 import org.aavso.tools.vstar.ui.dialog.MessageBox;
 import org.aavso.tools.vstar.ui.dialog.TextArea;
+import org.aavso.tools.vstar.ui.dialog.TextAreaTabs;
 import org.aavso.tools.vstar.ui.dialog.TextDialog;
 import org.aavso.tools.vstar.ui.mediator.Mediator;
 import org.aavso.tools.vstar.util.Pair;
@@ -44,6 +44,7 @@
 import org.aavso.tools.vstar.vela.AST;
 import org.aavso.tools.vstar.vela.Operand;
 import org.aavso.tools.vstar.vela.VeLaInterpreter;
+import org.aavso.tools.vstar.vela.VeLaPrefs;
 
 /**
  * A dialog in which to run VeLa code.
@@ -51,41 +52,45 @@
 @SuppressWarnings("serial")
 public class VeLaDialog extends TextDialog {
 
+    private static final String tabTextSeparator = "===---===";
+
     private static ITextComponent<String> codeTextArea;
-    private static TextArea resultTextArea;
-    private static JCheckBox verbosityCheckBox;
+    private static ITextComponent<String> resultTextArea;
 
     private static VeLaInterpreter vela;
 
+    private static String code = "";
+
     private String path;
 
-    static {
-        codeTextArea = new TextArea("VeLa Code", "", 12, 42, false, true);
+    private static List<ITextComponent<String>> createTextAreas() {
+        codeTextArea = new TextArea("VeLa Code", code, 12, 42, false, true);
         addKeyListener();
 
-        // resultTextArea = new TextAreaTabs(Arrays.asList("Output", "Error",
-        // "AST", "DOT"), Arrays.asList("", "", "", ""), 15, 70,
-        // true, true);
-        // resultTextArea = new TextAreaTabs(Arrays.asList("Output", "Error"),
-        // Arrays.asList("", ""), 10, 40, true, true);
-        resultTextArea = new TextArea("Output", "", 12, 42, true, true);
+        boolean diagnosticMode = VeLaPrefs.getDiagnosticMode();
+
+        if (diagnosticMode) {
+            resultTextArea = new TextAreaTabs(Arrays.asList("Output", "LISP AST", "DOT AST"), Arrays.asList("", "", ""), 15, 70,
+                    true, true, tabTextSeparator);
+        } else {
+            resultTextArea = new TextArea("Output", "", 12, 42, true, true);
+        }
 
         Font font = codeTextArea.getUIComponent().getFont();
         codeTextArea.getUIComponent().setFont(new Font(Font.MONOSPACED, Font.PLAIN, font.getSize()));
         resultTextArea.getUIComponent().setFont(new Font(Font.MONOSPACED, Font.PLAIN, font.getSize()));
 
-        verbosityCheckBox = new JCheckBox("Verbose?");
-        verbosityCheckBox.setSelected(false);
-        verbosityCheckBox.setVisible(false);
+        return Arrays.asList(codeTextArea, resultTextArea);
     }
 
     public VeLaDialog(String title) {
-        super(title, Arrays.asList(codeTextArea, resultTextArea), true, true);
+        super(title, createTextAreas(), true, true);
         path = "Untitled";
     }
 
     public VeLaDialog(String title, String code) {
         this(title);
+        VeLaDialog.code = code;
         codeTextArea.setValue(code);
     }
 
@@ -162,13 +167,17 @@ protected JPanel createButtonPane() {
         });
         panel.add(dismissButton);
 
-        panel.add(verbosityCheckBox);
-
         return panel;
     }
 
     // Helpers
 
+    @Override
+    protected void okAction() {
+        VeLaDialog.code = VeLaDialog.codeTextArea.getValue();
+        super.okAction();
+    }
+
     private static void addKeyListener() {
         JTextArea area = (JTextArea) (codeTextArea.getUIComponent());
         area.addKeyListener(new KeyAdapter() {
@@ -227,7 +236,7 @@ public void keyTyped(KeyEvent e) {
     }
 
     private void execute() {
-        boolean verbose = verbosityCheckBox.isSelected();
+        boolean diagnostic = VeLaPrefs.getDiagnosticMode();
 
         String text = codeTextArea.getValue();
 
@@ -247,8 +256,7 @@ private void execute() {
             Mediator.getUI().setScriptingStatus(true);
 
             // Compile and execute the code.
-            vela = new VeLaInterpreter(false, true, Collections.emptyList());
-            vela.setVerbose(verbose);
+            vela = new VeLaInterpreter(VeLaPrefs.getVerboseMode(), true, VeLaPrefs.getCodeDirsList());
 
             Pair<Optional<Operand>, AST> pair = vela.veLaToResultASTPair(text);
 
@@ -256,7 +264,7 @@ private void execute() {
 
             if (result.isPresent()) {
                 AST ast = pair.second;
-                if (verbose && ast != null) {
+                if (diagnostic && ast != null) {
                     lispAST = ast.toString();
                     dotAST = ast.toFullDOT();
                 }
@@ -295,15 +303,25 @@ private void execute() {
             Mediator.getUI().setScriptingStatus(false);
         }
 
-        resultTextArea.setValue(areaTabsPayload(output, error));
+        String result = output;
+        if (!error.isEmpty()) {
+            result += "\n";
+            result += error;
+        }
+
+        resultTextArea.setValue(areaTabsPayload(VeLaPrefs.getDiagnosticMode(), result, lispAST, dotAST));
     }
 
-    private String areaTabsPayload(String... strings) {
+    private String areaTabsPayload(boolean verbose, String... strings) {
         StringBuffer buf = new StringBuffer();
 
         for (String str : strings) {
             buf.append(str);
-            buf.append("\n");
+            if (verbose) {
+                buf.append(tabTextSeparator);
+            } else {
+                buf.append("\n");
+            }
         }
 
         return buf.toString().trim();
diff --git a/src/org/aavso/tools/vstar/vela/VeLaPrefs.java b/src/org/aavso/tools/vstar/vela/VeLaPrefs.java
new file mode 100644
index 00000000..bff90f0d
--- /dev/null
+++ b/src/org/aavso/tools/vstar/vela/VeLaPrefs.java
@@ -0,0 +1,131 @@
+/**
+ * VStar: a statistical analysis tool for variable star data.
+ * Copyright (C) 2009  AAVSO (http://www.aavso.org/)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
+ */
+package org.aavso.tools.vstar.vela;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.prefs.Preferences;
+
+/**
+ * VeLa preferences class.
+ */
+public class VeLaPrefs {
+
+    public final static String DEFAULT_CODE_DIR_STR = "";
+    public final static String DEFAULT_DIAGNOSTIC_MODE_STR = "false";
+    public final static String DEFAULT_VERBOSE_MODE_STR = "false";
+
+    private final static String PREFS_PREFIX = "VELA_";
+
+    private final static String CODE_DIRS = "CODE_DIRS";
+    private final static String DIAGNOSTIC_MODE = "DIAGNOSTIC_MODE";
+
+    private static Preferences prefs;
+
+    private static String codeDirs = DEFAULT_CODE_DIR_STR;
+    private static Boolean diagnosticMode = Boolean.parseBoolean(DEFAULT_DIAGNOSTIC_MODE_STR);
+    private static Boolean verboseMode = Boolean.parseBoolean(DEFAULT_VERBOSE_MODE_STR);
+    static {
+        // Create preferences node.
+        try {
+            prefs = Preferences.userNodeForPackage(VeLaPrefs.class);
+        } catch (Throwable t) {
+            // We need VStar to function in the absence of prefs.
+        }
+    }
+
+    // Preference value getters
+
+    public static String getCodeDirs() {
+        loadCodeDirs();
+        return codeDirs;
+    }
+
+    public static void setCodeDirs(String codeDirs) {
+        VeLaPrefs.codeDirs = codeDirs;
+        saveCodeDirs(codeDirs);
+    }
+
+    public static List<File> getCodeDirsList() {
+        getCodeDirs();
+
+        String[] dirs = codeDirs.split("\n");
+
+        List<File> dirList = new ArrayList<File>();
+
+        for (String dir : dirs) {
+            dirList.add(new File(dir));
+        }
+
+        return dirList;
+    }
+
+    public static boolean getDiagnosticMode() {
+        loadDiagnosticMode();
+        return diagnosticMode;
+    }
+
+    public static void setDiagnosticMode(Boolean diagnosticMode) {
+        VeLaPrefs.diagnosticMode = diagnosticMode;
+        saveDiagnosticMode(diagnosticMode);
+    }
+
+    // Note: uncertain that verbose mode is needed, so just stop at getter for now
+    public static boolean getVerboseMode() {
+        return verboseMode;
+    }
+
+    // Preference save/load methods
+
+    public static void saveCodeDirs(String codeDirs) {
+        try {
+            prefs.put(PREFS_PREFIX + CODE_DIRS, codeDirs);
+        } catch (Throwable t) {
+            // We need VStar to function in the absence of prefs.
+        }
+    }
+
+    public static void loadCodeDirs() {
+        try {
+            codeDirs = prefs.get(PREFS_PREFIX + CODE_DIRS, DEFAULT_CODE_DIR_STR);
+        } catch (Throwable t) {
+            // We need VStar to function in the absence of prefs.
+        }
+    }
+
+    public static void saveDiagnosticMode(Boolean diagnosticMode) {
+        try {
+            prefs.put(PREFS_PREFIX + DIAGNOSTIC_MODE, diagnosticMode.toString());
+        } catch (Throwable t) {
+            // We need VStar to function in the absence of prefs.
+        }
+    }
+
+    public static void loadDiagnosticMode() {
+        String modeStr = DEFAULT_DIAGNOSTIC_MODE_STR;
+
+        try {
+            modeStr = prefs.get(PREFS_PREFIX + DIAGNOSTIC_MODE, DEFAULT_DIAGNOSTIC_MODE_STR);
+        } catch (Throwable t) {
+            // We need VStar to function in the absence of prefs.
+        }
+
+        diagnosticMode = Boolean.parseBoolean(modeStr);
+    }
+}