--- a/core.windows/src/org/netbeans/core/windows/view/ui/MainWindow.java	
+++ a/core.windows/src/org/netbeans/core/windows/view/ui/MainWindow.java	
@@ -56,8 +56,10 @@ 
 import java.awt.GraphicsEnvironment;
 import java.awt.Image;
 import java.awt.Rectangle;
+import java.awt.Toolkit;
 import java.awt.event.*;
 import java.io.File;
+import java.lang.reflect.Field;
 import java.util.*;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -139,6 +141,17 @@ 
        if (mainMenuBar == null) {
            mainMenuBar = createMenuBar();
            ToolbarPool.getDefault().waitFinished();
+           Toolkit toolkit = Toolkit.getDefaultToolkit();
+           Class<?> xtoolkit = toolkit.getClass();
+           if (xtoolkit.getName().equals("sun.awt.X11.XToolkit")) {
+               try {
+                    final Field awtAppClassName = xtoolkit.getDeclaredField("awtAppClassName");
+                    awtAppClassName.setAccessible(true);
+                    awtAppClassName.set(null, NbBundle.getMessage(MainWindow.class, "CTL_MainWindow_Title_No_Project", "").trim());
+               } catch (Exception x) {
+                   LOGGER.log(Level.FINE, null, x);
+               }
+           }
        }
    }