diff -ru zoom-page-a/chrome/content/zoompage-browser.js zoom-page-b/chrome/content/zoompage-browser.js
--- zoom-page-a/chrome/content/zoompage-browser.js	2017-08-15 09:16:00.000000000 -0400
+++ zoom-page-b/chrome/content/zoompage-browser.js	2018-11-28 13:32:17.249047976 -0500
@@ -576,39 +576,7 @@
         var colors = new Array();
         
         window.removeEventListener("load",zoomPage.onLoad,false);
-        
-        /* Display legacy message - Firefox 57 will be released on 14 Nov 2017 */
-        
-        if (Date.now() >= Date.UTC(2017,10,7))  /* after 7 Nov 2017 - 1 week before Firefox 57 released */
-        {
-            if (zoomPage.prefs.getPrefType("legacythirdtime") == 0)
-            {
-                zoomPage.prefs.setBoolPref("legacydonotshow",false);
-                zoomPage.prefs.setBoolPref("legacythirdtime",true);
-            }
-        }
-        else if (Date.now() >= Date.UTC(2017,9,24))  /* after 24 Oct 2017 - 3 weeks before Firefox 57 released */
-        {
-            if (zoomPage.prefs.getPrefType("legacysecondtime") == 0)
-            {
-                zoomPage.prefs.setBoolPref("legacydonotshow",false);
-                zoomPage.prefs.setBoolPref("legacysecondtime",true);
-            }
-        }
-        else if (Date.now() >= Date.UTC(2017,9,3))  /* after 3 Oct 2017 - 6 weeks before Firefox 57 released */
-        {
-            if (zoomPage.prefs.getPrefType("legacyfirsttime") == 0)
-            {
-                zoomPage.prefs.setBoolPref("legacydonotshow",false);
-                zoomPage.prefs.setBoolPref("legacyfirsttime",true);
-            }
-        }
-        
-        if (!zoomPage.prefs.getBoolPref("legacydonotshow"))
-        {
-            window.openDialog("chrome://zoompage/content/zoompage-legacy.xul","","chrome,dialog,titlebar,centerscreen,alwaysRaised");
-        }
-        
+
         /* Determine Firefox version and set attribute */
         
         if (zoomPage.versionComparator.compare(zoomPage.appInfo.version,"34.0a1") >= 0) zoomPage.ffVersion = "34.0";
@@ -1773,7 +1741,7 @@
                 if (aVal < 1/100 || aVal > 10000/100)
                     throw Components.results.NS_ERROR_INVALID_ARG;
                 
-                if (zoomPage.ffVersion >= +"29.0")
+                if (zoomPage.ffVersion >= +"29.0" || zoomPage.ffPaleMoon)
                 {
                     aBrowser.textZoom = 1;
                     aBrowser.fullZoom = 1;
@@ -1799,7 +1767,7 @@
                 if (aVal < ZoomManager.MIN || aVal > ZoomManager.MAX)
                     throw Components.results.NS_ERROR_INVALID_ARG;
                 
-                if (zoomPage.ffVersion >= +"29.0")
+                if (zoomPage.ffVersion >= +"29.0" || zoomPage.ffPaleMoon /* PM28+ */)
                 {
                     if (ZoomManager.useFullZoom || aBrowser.isSyntheticDocument /* FF29+ */)
                     {
@@ -3310,7 +3278,7 @@
             zoomPage.setPercent(42);
         }
     },
-    
+
     onDOMContentLoaded: function(message)
     {
         var browser;
@@ -3430,10 +3398,14 @@
                 });
             });
         }
-        
-        if (browser.currentURI.spec.indexOf("#") != -1) zoomPage.onHashChange(message);
+	if ( !browser.currentURI ) {
+		return
+	}
+        else if (browser.currentURI.spec.indexOf("#") != -1) {
+		zoomPage.onHashChange(message);
+		}
     },
-    
+
     onHashChange: function(message)
     {
         var browser;
@@ -3484,7 +3456,7 @@
         }
         ,200,browser);  /* allow time for contents to update after URI hash changed */
     },
-    
+
     onTabSelect: function(event)
     {
         var browser;
Only in zoom-page-a/chrome/content: zoompage-legacy.xul
diff -ru zoom-page-a/install.rdf zoom-page-b/install.rdf
--- zoom-page-a/install.rdf	2017-08-15 09:16:00.000000000 -0400
+++ zoom-page-b/install.rdf	2018-11-28 08:44:29.972193992 -0500
@@ -30,16 +30,24 @@
         
         <em:multiprocessCompatible>true</em:multiprocessCompatible>
         
-        <em:targetApplication> <!-- Firefox -->
+        <em:targetApplication> <!-- Iceweasel-UXP/Basilisk -->
             <Description>
                 <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
                 <em:minVersion>4.0</em:minVersion>
                 <em:maxVersion>56.*</em:maxVersion>
             </Description>
         </em:targetApplication>
-        
+
+        <em:targetApplication> <!-- PaleMoon -->
+            <Description>
+                <em:id>{8de7fcbb-c55c-4fbe-bfc5-fc555c87dbc4}</em:id>
+                <em:minVersion>27.0</em:minVersion>
+                <em:maxVersion>28.*</em:maxVersion>
+            </Description>
+        </em:targetApplication>
+
     </Description>
     
 </RDF>
  
-     
\ No newline at end of file
+     
Only in zoom-page-a: META-INF