diff --git a/www/js/app.js b/www/js/app.js
index 4bfc3ad2..f05264de 100644
--- a/www/js/app.js
+++ b/www/js/app.js
@@ -1031,7 +1031,7 @@ document.getElementById('btnConfigure').addEventListener('click', function () {
         setTab();
         if (params.themeChanged) {
             params.themeChanged = false;
-            var archiveName = appstate.selectedArchive ? appstate.selectedArchive._file.name : null;
+            var archiveName = appstate.selectedArchive ? appstate.selectedArchive.file.name : null;
             if (archiveName && ~params.lastPageVisit.indexOf(archiveName)) {
                 goToArticle(params.lastPageVisit.replace(/@kiwixKey@.+$/, ''));
             }
@@ -1775,7 +1775,7 @@ document.getElementById('manipulateImagesCheck').addEventListener('click', funct
         } else if (window.nw) {
             uiUtil.systemAlert('Unfortunately there is currently no way to save an image to disk in the NWJS version of this app.<br>You can do this in the PWA version: please visit https://pwa.kiwix.org.');
         } else if (params.contentInjectionMode === 'serviceworker' && appstate.selectedArchive &&
-            !/wikipedia|wikivoyage|mdwiki|wiktionary/i.test(appstate.selectedArchive._file.name)) {
+            !/wikipedia|wikivoyage|mdwiki|wiktionary/i.test(appstate.selectedArchive.file.name)) {
             uiUtil.systemAlert('Please be aware that Image manipulation can interfere with non-Wikimedia ZIMs (particularly ZIMs that have active content). If you cannot access the articles in such a ZIM, please turn this setting off.');
         } else if (/PWA/.test(params.appType) && params.contentInjectionMode === 'jquery') {
             uiUtil.systemAlert('Be aware that this option may interfere with active content if you switch to Service Worker mode.');
@@ -3381,7 +3381,7 @@ function setLocalArchiveFromArchiveList (archive) {
                             readNodeDirectoryAndCreateNodeFileObjects(params.pickedFolder, archive)
                             .then(function (fileset) {
                                 var selectedFiles = fileset[0];
-                                if (appstate.selectedArchive && appstate.selectedArchive._file._files[0].name === selectedFiles[0].name) {
+                                if (appstate.selectedArchive && appstate.selectedArchive.file._files[0].name === selectedFiles[0].name) {
                                     document.getElementById('btnHome').click();
                                 } else {
                                     setLocalArchiveFromFileList(selectedFiles);
@@ -3947,18 +3947,18 @@ function archiveReadyCallback (archive) {
     // Ensure that the new ZIM output is initially sent to the iframe (e.g. if the last article was loaded in a window)
     // (this only affects jQuery mode)
     appstate.target = 'iframe';
-    appstate.wikimediaZimLoaded = /wikipedia|wikivoyage|mdwiki|wiktionary/i.test(archive._file.name);
+    appstate.wikimediaZimLoaded = /wikipedia|wikivoyage|mdwiki|wiktionary/i.test(archive.file.name);
     appstate.pureMode = false;
     // These ZIM types have so much dynamic content that we have to allow all images
-    if (params.imageDisplay && (/gutenberg|phet/i.test(archive._file.name) ||
+    if (params.imageDisplay && (/gutenberg|phet/i.test(archive.file.name) ||
     // params.isLandingPage ||
-    /kolibri/i.test(archive._file.creator) ||
+    /kolibri/i.test(archive.creator) ||
     params.zimType === 'zimit')) {
         params.imageDisplayMode = 'all';
         if (params.zimType !== 'zimit') {
             // For some archive types (Gutenberg, PhET, Kolibri at least), we have to get out of the way and allow the Service Worker
             // to act as a transparent passthrough (this key will be read in the handleMessageChannelMessage function)
-            console.debug('*** Activating pureMode for ZIM: ' + archive._file.name + ' ***');
+            console.debug('*** Activating pureMode for ZIM: ' + archive.file.name + ' ***');
             appstate.pureMode = true;
         }
     }
@@ -3992,8 +3992,8 @@ function archiveReadyCallback (archive) {
         }
     }
     // The archive is set : go back to home page to start searching
-    params.storedFile = archive._file._files[0].name;
-    params.storedFilePath = archive._file._files[0].path ? archive._file._files[0].path : '';
+    params.storedFile = archive.file._files[0].name;
+    params.storedFilePath = archive.file._files[0].path ? archive.file._files[0].path : '';
     settingsStore.setItem('lastSelectedArchive', params.storedFile, Infinity);
     settingsStore.setItem('lastSelectedArchivePath', params.storedFilePath, Infinity);
     if (!~params.lastPageVisit.indexOf(params.storedFile.replace(/\.zim(\w\w)?$/, ''))) {
@@ -4648,7 +4648,7 @@ function readArticle (dirEntry) {
                     uiUtil.clearSpinner();
                 });
             } else if (params.contentInjectionMode === 'serviceworker') {
-                articleContainer = window.open('../' + appstate.selectedArchive._file.name + '/' + dirEntry.namespace + '/' + encodeURIComponent(dirEntry.url),
+                articleContainer = window.open('../' + appstate.selectedArchive.file.name + '/' + dirEntry.namespace + '/' + encodeURIComponent(dirEntry.url),
                     params.windowOpener === 'tab' ? '_blank' : encodeURIComponent(dirEntry.title | mimeType),
                     params.windowOpener === 'window' ? 'toolbar=0,location=0,menubar=0,width=800,height=600,resizable=1,scrollbars=1' : null);
                 appstate.target = 'window';
@@ -4660,7 +4660,7 @@ function readArticle (dirEntry) {
         }
         // Load cached start page if it exists and we have loaded the packaged file
         var htmlContent = 0;
-        var zimName = appstate.selectedArchive._file.name.replace(/\.[^.]+$/, '').replace(/_\d+-\d+$/, '');
+        var zimName = appstate.selectedArchive.file.name.replace(/\.[^.]+$/, '').replace(/_\d+-\d+$/, '');
         if (params.isLandingPage && params.cachedStartPages[zimName]) {
             htmlContent = -1;
             // @TODO: Why are we double-encoding here????? Clearly we double-decode somewhere...
@@ -4777,7 +4777,7 @@ var loaded = false;
 var articleLoadedSW = function (dirEntry) {
     if (loaded) return;
     loaded = true;
-    params.lastPageVisit = dirEntry.namespace + '/' + dirEntry.url + '@kiwixKey@' + appstate.selectedArchive._file.name;
+    params.lastPageVisit = dirEntry.namespace + '/' + dirEntry.url + '@kiwixKey@' + appstate.selectedArchive.file.name;
     articleDocument = articleWindow.document.documentElement;
     var doc = articleWindow.document;
     var docBody = doc.body;
@@ -4812,7 +4812,7 @@ var articleLoadedSW = function (dirEntry) {
         listenForNavigationKeys();
         // We need to keep tabs on the opened tabs or windows if the user wants right-click functionality, and also parse download links
         // We need to set a timeout so that dynamically generated URLs are parsed as well (e.g. in Gutenberg ZIMs)
-        if (params.windowOpener) {
+        if (params.windowOpener && !appstate.pureMode) {
             setTimeout(function () {
                 parseAnchorsJQuery(dirEntry);
             }, 1500);
@@ -4973,7 +4973,7 @@ function handleMessageChannelMessage (event) {
                     } else {
                         loadingArticle = '';
                     }
-                    var cacheKey = appstate.selectedArchive._file.name + '/' + title;
+                    var cacheKey = appstate.selectedArchive.file.name + '/' + title;
                     cache.getItemFromCacheOrZIM(appstate.selectedArchive, cacheKey, dirEntry).then(function (content) {
                         console.debug('SW read binary file for: ' + dirEntry.namespace + '/' + dirEntry.url);
                         if (params.zimType === 'zimit' && loadingArticle) {
@@ -5051,7 +5051,7 @@ function postTransformedHTML (thisMessage, thisMessagePort, thisDirEntry) {
         if (/UWP/.test(params.appType) && (appstate.target === 'window' || appstate.messageChannelWaiting) &&
             params.imageDisplay) { thisMessage.imageDisplay = 'all'; }
         // We need to do the same for Gutenberg and PHET ZIMs
-        if (params.imageDisplay && (/gutenberg|phet/i.test(appstate.selectedArchive._file.name)
+        if (params.imageDisplay && (/gutenberg|phet/i.test(appstate.selectedArchive.file.name)
             // || params.isLandingPage
             )) {
             thisMessage.imageDisplay = 'all';
@@ -5203,21 +5203,21 @@ function displayArticleContentInContainer (dirEntry, htmlArticle) {
     // Since page has been successfully loaded, store it in the browser history
     if (params.contentInjectionMode === 'jquery') pushBrowserHistoryState(dirEntry.namespace + '/' + dirEntry.url);
     // Store for fast retrieval
-    params.lastPageVisit = dirEntry.namespace + '/' + dirEntry.url + '@kiwixKey@' + appstate.selectedArchive._file.name;
+    params.lastPageVisit = dirEntry.namespace + '/' + dirEntry.url + '@kiwixKey@' + appstate.selectedArchive.file.name;
     if (params.rememberLastPage) settingsStore.setItem('lastPageVisit', params.lastPageVisit, Infinity);
-    cache.setArticle(appstate.selectedArchive._file.name, dirEntry.namespace + '/' + dirEntry.url, htmlArticle, function () {});
+    cache.setArticle(appstate.selectedArchive.file.name, dirEntry.namespace + '/' + dirEntry.url, htmlArticle, function () {});
     params.htmlArticle = htmlArticle;
 
     // Replaces ZIM-style URLs of img, script, link and media tags with a data-kiwixurl to prevent 404 errors [kiwix-js #272 #376]
     // This replacement also processes the URL relative to the page's ZIM URL so that we can find the ZIM URL of the asset
     // with the correct namespace (this works for old-style -,I,J namespaces and for new-style C namespace)
-    if (params.linkToWikimediaImageFile && !params.isLandingPage && /(?:wikipedia|wikivoyage|wiktionary|mdwiki)_/i.test(appstate.selectedArchive._file.name)) {
-        var wikiLang = appstate.selectedArchive._file.name.replace(/(?:wikipedia|wikivoyage|wiktionary|mdwiki)_([^_]+).+/i, '$1');
-        var wikimediaZimFlavour = appstate.selectedArchive._file.name.replace(/_.+/, '');
+    if (params.linkToWikimediaImageFile && !params.isLandingPage && /(?:wikipedia|wikivoyage|wiktionary|mdwiki)_/i.test(appstate.selectedArchive.file.name)) {
+        var wikiLang = appstate.selectedArchive.file.name.replace(/(?:wikipedia|wikivoyage|wiktionary|mdwiki)_([^_]+).+/i, '$1');
+        var wikimediaZimFlavour = appstate.selectedArchive.file.name.replace(/_.+/, '');
     }
     var newBlock;
     var assetZIMUrlEnc;
-    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name) + '/';
+    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name) + '/';
     if (params.contentInjectionMode == 'jquery') {
         htmlArticle = htmlArticle.replace(params.regexpTagsWithZimUrl, function (match, blockStart, equals, quote, relAssetUrl, blockClose) {
             // Don't process data URIs (yet)
@@ -5284,7 +5284,7 @@ function displayArticleContentInContainer (dirEntry, htmlArticle) {
             // @TODO - remove when fixed on mw-offliner: dirty patch for removing extraneous tags in ids
             htmlArticle = htmlArticle.replace(/(\bid\s*=\s*"[^\s}]+)\s*\}[^"]*/g, '$1');
             // @TODO - remove when fixed in MDwiki ZIM: dirty patch for removing erroneously hard-coded style
-            if (/^mdwiki/.test(appstate.selectedArchive._file.name)) htmlArticle = htmlArticle.replace(/(class=['"]thumbinner[^>]+style=['"]width\s*:\s*)\d+px/ig, '$1320px');
+            if (/^mdwiki/.test(appstate.selectedArchive.file.name)) htmlArticle = htmlArticle.replace(/(class=['"]thumbinner[^>]+style=['"]width\s*:\s*)\d+px/ig, '$1320px');
             // Remove landing page scripts that don't work in SW mode
             htmlArticle = htmlArticle.replace(/<script\b[^>]+-\/[^>]*((?:images_loaded|masonry)\.min|article_list_home)\.js"[^<]*<\/script>/gi, '');
             // Set max-width for infoboxes (now set in -/s/styles.css)
@@ -5399,7 +5399,7 @@ function displayArticleContentInContainer (dirEntry, htmlArticle) {
         ? false : params.useMathJax;
     // Detect raw MathML on page for certain ZIMs that are expected to have it
     params.containsMathTexRaw = params.useMathJax &&
-        /stackexchange|askubuntu|superuser|stackoverflow|mathoverflow|serverfault|stackapps|proofwiki/i.test(appstate.selectedArchive._file.name)
+        /stackexchange|askubuntu|superuser|stackoverflow|mathoverflow|serverfault|stackapps|proofwiki/i.test(appstate.selectedArchive.file.name)
         ? /[^\\](\$\$?)((?:\\\$|(?!\1)[\s\S])+)\1/.test(htmlArticle) : false;
 
     // if (params.containsMathTexRaw) {
@@ -5572,7 +5572,7 @@ function displayArticleContentInContainer (dirEntry, htmlArticle) {
             blobArray.push([title, cssBlobCache.get(title)]);
             injectCSS();
         } else {
-            var cacheKey = appstate.selectedArchive._file.name + '/' + title;
+            var cacheKey = appstate.selectedArchive.file.name + '/' + title;
             cache.getItemFromCacheOrZIM(appstate.selectedArchive, cacheKey).then(function (content) {
                 // DEV: Uncomment line below and break on next to capture cssContent for local filesystem cache
                 // var cssContent = util.uintToString(content);
@@ -5884,7 +5884,7 @@ function displayArticleContentInContainer (dirEntry, htmlArticle) {
             // If the request was not initiated by an existing controlled window, we instantiate the request here
             if (!appstate.messageChannelWaiting) {
                 // We put the ZIM filename as a prefix in the URL, so that browser caches are separate for each ZIM file
-                var newLocation = '../' + appstate.selectedArchive._file.name + '/' + dirEntry.namespace + '/' + encodedUrl;
+                var newLocation = '../' + appstate.selectedArchive.file.name + '/' + dirEntry.namespace + '/' + encodedUrl;
                 if (navigator.serviceWorker.controller) {
                     loaded = false;
                     articleWindow.location.href = newLocation;
@@ -6053,7 +6053,7 @@ function addListenersToLink (a, href, baseUrl) {
         e.stopPropagation();
         anchorParameter = href.match(/#([^#;]+)$/);
         anchorParameter = anchorParameter ? anchorParameter[1] : '';
-        var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name) + '/';
+        var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name) + '/';
         var zimRoot = indexRoot.replace(/^.+?\/www\//, '/');
         var zimUrl;
         var zimUrlFullEncoding;
@@ -6398,7 +6398,7 @@ function goToArticle (path, download, contentType, pathEnc) {
     clearFindInArticle();
     var shortTitle = path.replace(/[^/]+\//g, '').substring(0, 18);
     uiUtil.pollSpinner('Loading ' + shortTitle);
-    var zimName = appstate.selectedArchive._file.name.replace(/\.[^.]+$/, '').replace(/_\d+-\d+$/, '');
+    var zimName = appstate.selectedArchive.file.name.replace(/\.[^.]+$/, '').replace(/_\d+-\d+$/, '');
     if (~path.indexOf(params.cachedStartPages[zimName])) {
         goToMainArticle();
         return;
@@ -6426,7 +6426,7 @@ function goToArticle (path, download, contentType, pathEnc) {
         } else if (download || /\/(epub|pdf|zip|.*opendocument|.*officedocument|tiff|mp4|webm|mpeg|octet-stream)\b/i.test(mimetype)) {
             // PDFs can be treated as a special case, as they can be displayed directly in a browser window or tab in most browsers (but not UWP)
             if (!/UWP/.test(params.appType) && params.contentInjectionMode === 'serviceworker' && (/\/pdf\b/.test(mimetype) || /\.pdf([?#]|$)/i.test(dirEntry.url))) {
-                window.open(document.location.pathname.replace(/[^/]+$/, '') + appstate.selectedArchive._file.name + '/' + pathForServiceWorker,
+                window.open(document.location.pathname.replace(/[^/]+$/, '') + appstate.selectedArchive.file.name + '/' + pathForServiceWorker,
                     params.windowOpener === 'tab' ? '_blank' : 'Download PDF',
                     params.windowOpener === 'window' ? 'toolbar=0,location=0,menubar=0,width=800,height=600,resizable=1,scrollbars=1' : null);
             } else {
@@ -6462,7 +6462,7 @@ function goToRandomArticle () {
                 // We fall back to the old A namespace to support old ZIM files without a text/html MIME type for articles
                 // DEV: If minorVersion is 1, then we are using a v1 article-only title listing. By definition,
                 // all dirEntries in an article-only listing must be articles.
-                if (appstate.selectedArchive._file.minorVersion === 1 || /text\/html\b/i.test(dirEntry.getMimetype()) ||
+                if (appstate.selectedArchive.file.minorVersion === 1 || /text\/html\b/i.test(dirEntry.getMimetype()) ||
                     params.zimType !== 'zimit' && dirEntry.namespace === 'A') {
                     params.isLandingPage = false;
                     alertBoxHeader.style.display = 'none';
diff --git a/www/js/lib/images.js b/www/js/lib/images.js
index f25a4ba7..59462824 100644
--- a/www/js/lib/images.js
+++ b/www/js/lib/images.js
@@ -105,7 +105,7 @@ function extractImages (images, callback) {
             return;
         }
         // Zimit files (at least) will sometimes have a ZIM prefix, but we are extracting raw here
-        title = title.replace(appstate.selectedArchive._file.name + '/', '');
+        title = title.replace(appstate.selectedArchive.file.name + '/', '');
         // Zimit files store URLs encoded!
         if (params.zimType === 'zimit') title = encodeURI(title);
         appstate.selectedArchive.getDirEntryByPath(title).then(function (dirEntry) {
@@ -242,7 +242,7 @@ function prepareImagesServiceWorker (win, forPrinting) {
     }, 1000);
     if (!forPrinting && !documentImages.length) return;
     var imageHtml;
-    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name) + '/';
+    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name) + '/';
     for (var i = 0, l = documentImages.length; i < l; i++) {
         // Process Wikimedia MathML, but not if we'll be using the jQuery routine later
         if (!(params.manipulateImages || params.allowHTMLExtraction)) {
@@ -312,7 +312,7 @@ function prepareImagesJQuery (win, forPrinting) {
     container = win;
     var doc = container.document;
     var documentImages = doc.querySelectorAll('img[data-kiwixurl], video, audio');
-    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name) + '/';
+    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name) + '/';
     indexRoot = indexRoot.replace(/^\//, '');
     // Zimit ZIMs work better if all images are extracted
     if (params.zimType === 'zimit') forPrinting = true;
@@ -331,7 +331,7 @@ function prepareImagesJQuery (win, forPrinting) {
             image.style.opacity = '0';
             // Set a minimum width to avoid some images not rendering in squashed hidden tables
             if (params.displayHiddenBlockElements && image.width && !image.style.minWidth &&
-                /wiki|wiktionary/i.test(appstate.selectedArchive._file.name)) {
+                /wiki|wiktionary/i.test(appstate.selectedArchive.file.name)) {
                 var imgX = image.width + '';
                 imgX = imgX.replace(/(\d+)$/, '$1px');
                 image.style.minWidth = imgX;
diff --git a/www/js/lib/transformZimit.js b/www/js/lib/transformZimit.js
index 16b0a0aa..0bd33fb8 100644
--- a/www/js/lib/transformZimit.js
+++ b/www/js/lib/transformZimit.js
@@ -131,7 +131,7 @@ function transformReplayUrls (dirEntry, data, mimetype, callback) {
      * Note that some Zimit ZIMs have mimeteypes like 'text/html;raw=true', so we can't simply match 'text/html'
      * Other ZIMs have a mimetype like 'html' (with no 'text/'), so we have to match as generically as possible
      */
-    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name);
+    var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name);
     if (/\bx?html\b/i.test(mimetype)) {
         var zimitPrefix = data.match(regexpGetZimitPrefix);
         // If the URL is the same as the URL with everything after the first / removed, then we are in the root directory
@@ -320,7 +320,7 @@ function transformVideoUrl (url, articleDocument, callback) {
                             console.debug('TRANSFORMED VIDEO URL ' + pureUrl + ' --> \n' + transUrl);
                             // If we are dealing with embedded video, we have to find the embedded URL and subsitute it
                             if (/\/embed\//i.test(pureUrl)) {
-                                var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive._file.name);
+                                var indexRoot = window.location.pathname.replace(/[^/]+$/, '') + encodeURI(appstate.selectedArchive.file.name);
                                 Array.prototype.slice.call(articleDocument.querySelectorAll('iframe')).forEach(function (frame) {
                                     if (~frame.src.indexOf(videoId)) {
                                         var newUrl = window.location.origin + indexRoot + transUrl.replace(/videoembed/, '');
diff --git a/www/js/lib/uiUtil.js b/www/js/lib/uiUtil.js
index 5d84a3d9..be8c61ea 100644
--- a/www/js/lib/uiUtil.js
+++ b/www/js/lib/uiUtil.js
@@ -399,7 +399,7 @@ function displayActiveContentWarning (type) {
             (params.contentInjectionMode === 'jquery' ? '<b>Limited Zimit support!</b> Please <a id="swModeLink" href="#contentInjectionModeDiv" ' +
             'class="alert-link">switch to Service Worker mode</a> if your platform supports it. '
                 : 'Support for <b>Zimit</b> archives is experimental. Some content (e.g. audio/video) may fail. ') +
-            'You can search for content above' + (appstate.selectedArchive._file.fullTextIndex ? ' using full-text search if your app supports it, ' +
+            'You can search for content above' + (appstate.selectedArchive.file.fullTextIndex ? ' using full-text search if your app supports it, ' +
             'or s' : '. S') + 'tart your search with <b>.*</b> to match part of a title. Type a <b><i>space</i></b> for the ZIM Archive Index, or ' +
             '<b><i>space / </i></b> for the URL Index.&nbsp;[<a id="stop" href="#expertSettingsDiv" class="alert-link">Permanently hide</a>]' +
         '</div>';
diff --git a/www/js/lib/zimArchive.js b/www/js/lib/zimArchive.js
index 1f0e26f3..099824a3 100644
--- a/www/js/lib/zimArchive.js
+++ b/www/js/lib/zimArchive.js
@@ -1,22 +1,22 @@
 /**
  * zimArchive.js: Support for archives in ZIM format.
  *
- * Copyright 2015 Mossroy and contributors
- * License GPL v3:
+ * Copyright 2015-2023 Mossroy, Jaifroid and contributors
+ * Licence GPL v3:
  *
  * This file is part of Kiwix.
  *
  * Kiwix is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
+ * it under the terms of the GNU General Public Licence as published by
+ * the Free Software Foundation, either version 3 of the Licence, or
  * (at your option) any later version.
  *
  * Kiwix 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 General Public License for more details.
+ * GNU General Public Licence for more details.
  *
- * You should have received a copy of the GNU General Public License
+ * You should have received a copy of the GNU General Public Licence
  * along with Kiwix (file LICENSE-GPLv3.txt).  If not, see <http://www.gnu.org/licenses/>
  */
 
@@ -34,10 +34,17 @@ import utf8 from './utf8.js';
 /**
  * ZIM Archive
  *
- *
  * @typedef ZIMArchive
- * @property {ZIMFile} _file The ZIM file (instance of ZIMFile, that might physically be split into several actual files)
- * @property {String} _language Language of the content
+ * @property {ZIMFile} file The ZIM file (instance of ZIMFile, that might physically be split into several actual _files)
+ * @property {String} counter Counter of various types of content in the archive
+ * @property {String} creator Creator of the content
+ * @property {String} date Date of the creation of the archive
+ * @property {String} description Description of the content
+ * @property {String} language Language of the content
+ * @property {String} name Name of the archive
+ * @property {String} publisher Publisher of the content
+ * @property {String} title Title of the content
+ * @property {String} zimType Extended property: currently either 'open' for OpenZIM file type, or 'zimit' for the warc2zim file type used by Zimit
  */
 
 /**
@@ -66,17 +73,16 @@ var LZ;
  */
 function ZIMArchive (storage, path, callbackReady, callbackError) {
     var that = this;
-    that._file = null;
-    that._language = ''; // @TODO
+    that.file = null;
     var createZimfile = function (fileArray) {
         zimfile.fromFileArray(fileArray).then(function (file) {
-            that._file = file;
+            that.file = file;
             // Clear the previous libzimWoker
             LZ = null;
             // Set a global parameter to report the search provider type
             params.searchProvider = 'title';
             // File has been created, but we need to add any Listings which extend the archive metadata
-            that._file.setListings([
+            that.file.setListings([
                 // Provide here any Listings for which we need to extract metadata as key:value obects to be added to the file
                 // 'ptrName' and 'countName' contain the key names to be set in the archive file object
                 {
@@ -100,16 +106,16 @@ function ZIMArchive (storage, path, callbackReady, callbackError) {
                 }
             ]).then(function () {
                 // There is currently an exception thrown in the libzim wasm if we attempt to load a split ZIM archive, so we work around
-                var isSplitZim = /\.zima.$/i.test(that._file._files[0].name);
+                var isSplitZim = /\.zima.$/i.test(that.file._files[0].name);
                 var libzimReaderType = params.debugLibzimASM || ('WebAssembly' in self ? 'wasm' : 'asm');
-                if (that._file.fullTextIndex && params.debugLibzimASM !== 'disable' && (params.debugLibzimASM || !isSplitZim &&
+                if (that.file.fullTextIndex && params.debugLibzimASM !== 'disable' && (params.debugLibzimASM || !isSplitZim &&
                 // The ASM implementation requires Atomics support, whereas the WASM implementation does not
                 (typeof Atomics !== 'undefined' || libzimReaderType === 'wasm') &&
                 // Note that NWJS currently throws due to problems with Web Worker context, and Android is very slow unless we use OPFS
-                !(/Android/.test(params.appType) && !params.useOPFS) && !(window.nw && that._file._files[0].readMode === 'electron'))) {
+                !(/Android/.test(params.appType) && !params.useOPFS) && !(window.nw && that.file._files[0].readMode === 'electron'))) {
                     console.log('Instantiating libzim ' + libzimReaderType + ' Web Worker...');
                     LZ = new Worker('js/lib/libzim-' + libzimReaderType + '.js');
-                    that.callLibzimWorker({ action: 'init', files: that._file._files }).then(function (msg) {
+                    that.callLibzimWorker({ action: 'init', files: that.file._files }).then(function (msg) {
                         // console.debug(msg);
                         params.searchProvider = 'fulltext: ' + libzimReaderType;
                         // Update the API panel
@@ -120,7 +126,7 @@ function ZIMArchive (storage, path, callbackReady, callbackError) {
                     });
                 } else {
                     // var message = 'Full text searching is not available because ';
-                    if (!that._file.fullTextIndex) {
+                    if (!that.file.fullTextIndex) {
                         params.searchProvider += ': no_fulltext'; // message += 'this ZIM does not have a full-text index.';
                     } else if (isSplitZim) {
                         params.searchProvider += ': split_zim'; // message += 'the ZIM archive is split.';
@@ -134,24 +140,35 @@ function ZIMArchive (storage, path, callbackReady, callbackError) {
                         params.searchProvider += ': unknown';
                     }
                     uiUtil.reportSearchProviderToAPIStatusPanel(params.searchProvider);
-                    // uiUtil.systemAlert(message);
                 }
                 // Set the archive file type ('open' or 'zimit')
                 params.zimType = that.setZimType();
-                // var thisCallbackReady = callbackReady;
-                // Add any metadata from the M/ namespace that you need access to here
+                // Add time-critical metadata from the M/ namespace that you need early access to here
+                // Note that adding metadata here delays the reporting of the ZIM archive as ready
+                // Further metadata are added in the background below, and can be accessed later
                 Promise.all([
                     that.addMetadataToZIMFile('Creator'),
-                    that.addMetadataToZIMFile('Name')
+                    that.addMetadataToZIMFile('Language')
                 ]).then(function () {
-                    // If the arhchive name doesn't end in `.zim`, we add it to the metadata
-                    that._file.name = that._file.name.replace(/\.zim\s*$/i, '') + '.zim';
+                    console.debug('ZIMArchive ready, metadata will be added in the background');
+                    // All listings should be loaded, so we can now call the callback
                     callbackReady(that);
                 });
-                // DEV: Currently, extended listings are only used for title (=article) listings when the user searches
-                // for an article or uses the Random button, by which time the listings will have been extracted.
-                // If, in the future, listings are used in a more time-critical manner, consider forcing a wait before
-                // declaring the archive to be ready, by chaining the following callback in a .then() function of setListings.
+                // Add non-time-critical metadata to archive in background so as not to delay opening of the archive
+                // DEV: Note that it does not make sense to extract illustration (icon) metadata here. Instead, if you implement use of the illustration
+                // metadata as icons for the loaded ZIM [kiwix-js #886], you should simply use the ZIMArdhive.getMetadata() function when needed
+                setTimeout(function () {
+                    Promise.all([
+                        that.addMetadataToZIMFile('Counter'),
+                        that.addMetadataToZIMFile('Date'),
+                        that.addMetadataToZIMFile('Description'),
+                        that.addMetadataToZIMFile('Name'),
+                        that.addMetadataToZIMFile('Publisher'),
+                        that.addMetadataToZIMFile('Title')
+                    ]).then(function () {
+                        console.debug('ZIMArchive metadata loaded:', that);
+                    });
+                }, 1500);
             }).catch(function (err) {
                 console.warn('Error setting archive listings: ', err);
             });
@@ -208,27 +225,27 @@ ZIMArchive.prototype._searchArchiveParts = function (storage, prefixPath) {
  * @returns {Boolean}
  */
 ZIMArchive.prototype.isReady = function () {
-    return this._file !== null;
+    return this.file !== null;
 };
 
 /**
  * Detects whether the supplied archive is a Zimit-style archive or an OpenZIM archive and
- * sets a _file.zimType property accordingly; also returns the detected type. Extends ZIMFile.
+ * sets a zimType property accordingly; also returns the detected type. Extends ZIMArchive.
  * @returns {String} Either 'zimit' for a Zimit archive, or 'open' for an OpenZIM archive
  */
 ZIMArchive.prototype.setZimType = function () {
-    var fileType = null;
+    var archiveType = null;
     if (this.isReady()) {
-        fileType = 'open';
-        this._file.mimeTypes.forEach(function (v) {
-            if (/warc-headers/i.test(v)) fileType = 'zimit';
+        archiveType = 'open';
+        this.file.mimeTypes.forEach(function (v) {
+            if (/warc-headers/i.test(v)) archiveType = 'zimit';
         });
-        this._file.zimType = fileType;
-        console.debug('Archive type set to: ' + fileType);
+        this.zimType = archiveType;
+        console.debug('Archive type set to: ' + archiveType);
     } else {
         console.error('ZIMArchive is not ready! Cannot set ZIM type.');
     }
-    return fileType;
+    return archiveType;
 };
 
 /**
@@ -238,11 +255,11 @@ ZIMArchive.prototype.setZimType = function () {
  */
 ZIMArchive.prototype.getMainPageDirEntry = function (callback) {
     if (this.isReady()) {
-        var mainPageUrlIndex = this._file.mainPage;
+        var mainPageUrlIndex = this.file.mainPage;
         var that = this;
-        this._file.dirEntryByUrlIndex(mainPageUrlIndex).then(function (dirEntry) {
+        this.file.dirEntryByUrlIndex(mainPageUrlIndex).then(function (dirEntry) {
             // Filter out Zimit files that we cannot handle without error
-            if (that._file.zimType === 'zimit') dirEntry = transformZimit.filterReplayFiles(dirEntry);
+            if (that.zimType === 'zimit') dirEntry = transformZimit.filterReplayFiles(dirEntry);
             callback(dirEntry);
         });
     }
@@ -254,7 +271,7 @@ ZIMArchive.prototype.getMainPageDirEntry = function (callback) {
  * @returns {DirEntry}
  */
 ZIMArchive.prototype.parseDirEntryId = function (dirEntryId) {
-    return zimDirEntry.DirEntry.fromStringId(this._file, dirEntryId);
+    return zimDirEntry.DirEntry.fromStringId(this.file, dirEntryId);
 };
 
 /**
@@ -318,7 +335,7 @@ ZIMArchive.prototype.findDirEntriesWithPrefix = function (search, callback, noIn
     var prefixNameSpaces = '';
     if (search.searchUrlIndex) {
         var rgxSplitPrefix = /^[-ABCHIJMUVWX]\//;
-        if (that._file.zimType === 'zimit' && cns === 'C') {
+        if (that.zimType === 'zimit' && cns === 'C') {
             // We have to account for the Zimit prefix in Type 1 ZIMs
             rgxSplitPrefix = /^(?:[CMWX]\/)?(?:[AH]\/)?/;
         }
@@ -425,7 +442,7 @@ ZIMArchive.prototype.findDirEntriesWithPrefix = function (search, callback, noIn
 ZIMArchive.prototype.getContentNamespace = function () {
     var errorText;
     if (this.isReady()) {
-        var ver = this._file.minorVersion;
+        var ver = this.file.minorVersion;
         // DEV: There are currently only two defined values for minorVersion in the OpenZIM specification
         // If this changes, adapt the error checking and return values
         if (ver > 1) {
@@ -455,11 +472,11 @@ ZIMArchive.prototype.findDirEntriesWithPrefixCaseSensitive = function (prefix, s
     prefix = prefix || '';
     var cns = this.getContentNamespace();
     // Search v1 article listing if available, otherwise fallback to v0
-    var articleCount = this._file.articleCount || this._file.entryCount;
-    var searchFunction = appstate.selectedArchive._file.dirEntryByTitleIndex;
+    var articleCount = this.file.articleCount || this.file.entryCount;
+    var searchFunction = appstate.selectedArchive.file.dirEntryByTitleIndex;
     if (search.searchUrlIndex) {
-        articleCount = this._file.entryCount;
-        searchFunction = appstate.selectedArchive._file.dirEntryByUrlIndex;
+        articleCount = this.file.entryCount;
+        searchFunction = appstate.selectedArchive.file.dirEntryByUrlIndex;
     }
     util.binarySearch(startIndex, articleCount, function(i) {
         return searchFunction(i).then(function(dirEntry) {
@@ -488,7 +505,7 @@ ZIMArchive.prototype.findDirEntriesWithPrefixCaseSensitive = function (prefix, s
         });
     }, true).then(function (firstIndex) {
         var vDirEntries = [];
-        var addDirEntries = function(index, lastTitle) {
+        var addDirEntries = function (index, lastTitle) {
             if (search.status === 'cancelled' || search.found >= search.size || index >= articleCount
             || lastTitle && !~lastTitle.indexOf(prefix) || index - firstIndex >= search.window) {
                 // DEV: Diagnostics to be removed before merge
@@ -543,7 +560,7 @@ ZIMArchive.prototype.findDirEntriesFromFullTextSearch = function (search, dirEnt
     // We give ourselves an overhead in caclulating the results needed, because full-text search will return some results already found
     // var resultsNeeded = Math.floor(params.maxSearchResultsSize - dirEntries.length / 2);
     var resultsNeeded = number || params.maxSearchResultsSize;
-    return this.callLibzimWorker({action: "search", text: search.prefix, numResults: resultsNeeded}).then(function (results) {
+    return this.callLibzimWorker({ action: 'search', text: search.prefix, numResults: resultsNeeded }).then(function (results) {
         if (results) {
             var dirEntryPaths = [];
             var fullTextPaths = [];
@@ -614,10 +631,10 @@ ZIMArchive.prototype.callLibzimWorker = function (parameters) {
  * @param {DirEntry} dirEntry
  * @param {callbackDirEntry} callback
  */
-ZIMArchive.prototype.resolveRedirect = function(dirEntry, callback) {
+ZIMArchive.prototype.resolveRedirect = function (dirEntry, callback) {
     var that = this;
-    this._file.dirEntryByUrlIndex(dirEntry.redirectTarget).then(function (resolvedDirEntry) {
-        if (that._file.zimType === 'zimit') resolvedDirEntry = transformZimit.filterReplayFiles(resolvedDirEntry);
+    this.file.dirEntryByUrlIndex(dirEntry.redirectTarget).then(function (resolvedDirEntry) {
+        if (that.zimType === 'zimit') resolvedDirEntry = transformZimit.filterReplayFiles(resolvedDirEntry);
         callback(resolvedDirEntry);
     });
 };
@@ -632,7 +649,7 @@ ZIMArchive.prototype.resolveRedirect = function(dirEntry, callback) {
  * @param {DirEntry} dirEntry
  * @param {callbackStringContent} callback
  */
-ZIMArchive.prototype.readUtf8File = function(dirEntry, callback) {
+ZIMArchive.prototype.readUtf8File = function (dirEntry, callback) {
     var cns = appstate.selectedArchive.getContentNamespace();
     return dirEntry.readData().then(function(data) {
         var mimetype = dirEntry.getMimetype();
@@ -691,7 +708,7 @@ ZIMArchive.prototype.readUtf8File = function(dirEntry, callback) {
  * @param {DirEntry} dirEntry
  * @param {callbackBinaryContent} callback
  */
-ZIMArchive.prototype.readBinaryFile = function(dirEntry, callback) {
+ZIMArchive.prototype.readBinaryFile = function (dirEntry, callback) {
     var that = this;
     return dirEntry.readData().then(function(data) {
         var mimetype = dirEntry.getMimetype();
@@ -720,7 +737,7 @@ ZIMArchive.prototype.readBinaryFile = function(dirEntry, callback) {
  * @param {String} originalPath Optional string used internally to prevent infinite loop
  * @return {Promise<DirEntry>} A Promise that resolves to a Directory Entry, or null if not found.
  */
-ZIMArchive.prototype.getDirEntryByPath = function(path, zimitResolving, originalPath) {
+ZIMArchive.prototype.getDirEntryByPath = function (path, zimitResolving, originalPath) {
     var that = this;
     if (originalPath) appstate.originalPath = originalPath;
     path = path.replace(/\?kiwix-display/, '');
@@ -729,14 +746,14 @@ ZIMArchive.prototype.getDirEntryByPath = function(path, zimitResolving, original
         var revisedPath = path.replace(/.*?((?:C\/A|A)\/(?!.*(?:C\/A|A)).+)$/, '$1');
         if (revisedPath !== path) {
             console.warn('*** Revised path from ' + path + '\nto: ' + revisedPath + ' ***');
-            if (appstate.selectedArchive._file.zimType === 'zimit') {
+            if (appstate.selectedArchive.zimType === 'zimit') {
                 console.debug('*** DEV: Consider correcting this error in tranformZimit.js ***');
             }
             path = revisedPath;
         }
     }
-    return util.binarySearch(0, this._file.entryCount, function(i) {
-        return that._file.dirEntryByUrlIndex(i).then(function(dirEntry) {
+    return util.binarySearch(0, this.file.entryCount, function(i) {
+        return that.file.dirEntryByUrlIndex(i).then(function(dirEntry) {
             var url = dirEntry.namespace + "/" + dirEntry.url;
             if (path < url) {
                 return -1;
@@ -748,15 +765,15 @@ ZIMArchive.prototype.getDirEntryByPath = function(path, zimitResolving, original
         });
     }).then(function (index) {
         if (index === null) return null;
-        return that._file.dirEntryByUrlIndex(index);
+        return that.file.dirEntryByUrlIndex(index);
     }).then(function (dirEntry) {
         // Filter Zimit dirEntries and do somee initial transforms
-        if (that._file.zimType === 'zimit') {
+        if (that.zimType === 'zimit') {
             dirEntry = transformZimit.filterReplayFiles(dirEntry);
         }
         if (!dirEntry) {
             // We couldn't get the dirEntry, so look it up the Zimit header
-            if (!zimitResolving && that._file.zimType === 'zimit' && !/^(H|C\/H)\//.test(path) && path !== appstate.originalPath) {
+            if (!zimitResolving && that.zimType === 'zimit' && !/^(H|C\/H)\//.test(path) && path !== appstate.originalPath) {
                 // We need to look the file up in the Header namespace (double replacement ensures both types of ZIM are supported)
                 var oldPath = path;
                 path = path.replace(/^A\//, 'H/').replace(/^(C\/)A\//, '$1H/');
@@ -831,9 +848,9 @@ function fuzzySearch(path, search) {
  */
 ZIMArchive.prototype.getRandomDirEntry = function (callback) {
     // Prefer an article-only (v1) title pointer list, if available
-    var articleCount = this._file.articleCount || this._file.entryCount;
+    var articleCount = this.file.articleCount || this.file.entryCount;
     var index = Math.floor(Math.random() * articleCount);
-    this._file.dirEntryByTitleIndex(index).then(callback);
+    this.file.dirEntryByTitleIndex(index).then(callback);
 };
 
 /**
@@ -869,7 +886,7 @@ ZIMArchive.prototype.addMetadataToZIMFile = function (key) {
     return new Promise(function (resolve, reject) {
         that.getMetadata(key, function (data) {
             data = data || '';
-            that._file[lcaseKey] = data;
+            that[lcaseKey] = data;
             resolve(data);
         });
     });
@@ -877,4 +894,4 @@ ZIMArchive.prototype.addMetadataToZIMFile = function (key) {
 
 export default {
     ZIMArchive: ZIMArchive
-};
\ No newline at end of file
+};
diff --git a/www/js/lib/zimfile.js b/www/js/lib/zimfile.js
index ab67a53b..50f3739d 100644
--- a/www/js/lib/zimfile.js
+++ b/www/js/lib/zimfile.js
@@ -2,24 +2,28 @@
  * zimfile.js: Low-level ZIM file reader.
  *
  * Copyright 2015 Mossroy and contributors
- * License GPL v3:
+ * Licence GPL v3:
  *
  * This file is part of Kiwix.
  *
  * Kiwix is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
+ * it under the terms of the GNU General Public Licence as published by
+ * the Free Software Foundation, either version 3 of the Licence, or
  * (at your option) any later version.
  *
  * Kiwix 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 General Public License for more details.
+ * GNU General Public Licence for more details.
  *
- * You should have received a copy of the GNU General Public License
+ * You should have received a copy of the GNU General Public Licence
  * along with Kiwix (file LICENSE-GPLv3.txt).  If not, see <http://www.gnu.org/licenses/>
  */
 
+'use strict';
+
+/* global params, appstate */
+
 import xz from './xzdec_wrapper.js';
 import zstd from './zstddec_wrapper.js';
 import util from './util.js';
@@ -27,10 +31,6 @@ import utf8 from './utf8.js';
 import zimDirEntry from './zimDirEntry.js';
 import FileCache from './filecache.js';
 
-/* global params, appstate */
-
-'use strict';
-
 /**
  * This code makes an assumption that no Directory Entry will be larger that MAX_SUPPORTED_DIRENTRY_SIZE bytes.
  * If a larger dirEntry is encountered, a warning will display in console. Increase this value if necessary.
@@ -112,7 +112,6 @@ var readInt = function (data, offset, size) {
  * @property {Integer} mimeListPos Position of the MIME type list (also header size)
  * @property {Integer} mainPage Main page or 0xffffffff if no main page
  * @property {Integer} layoutPage Layout page or 0xffffffffff if no layout page
- * @property {String} zimType Extended property: currently either 'open' for OpenZIM file type, or 'zimit' for the warc2zim file type used by Zimit (set in zimArchive.js)
  * @property {Map} mimeTypes Extended property: the ZIM file's MIME type table rendered as a Map (calculated entry)
  */
 
@@ -230,7 +229,7 @@ ZIMFile.prototype.dirEntry = function (offset) {
  * @returns {Promise<DirEntry>} A Promise for the requested DirEntry
  */
 ZIMFile.prototype.dirEntryByUrlIndex = function (index) {
-    var that = appstate.selectedArchive._file;
+    var that = appstate.selectedArchive.file;
     if (!that) return Promise.resolve(null);
     return that._readInteger(that.urlPtrPos + index * 8, 8).then(function (dirEntryPos) {
         return that.dirEntry(dirEntryPos);
@@ -243,7 +242,7 @@ ZIMFile.prototype.dirEntryByUrlIndex = function (index) {
  * @returns {Promise<DirEntry>} A Promise for the requested DirEntry
  */
 ZIMFile.prototype.dirEntryByTitleIndex = function (index) {
-    var that = appstate.selectedArchive._file;
+    var that = appstate.selectedArchive.file;
     // Use v1 title pointerlist if available, or fall back to legacy v0 list
     var ptrList = that.articlePtrPos || that.titlePtrPos;
     return that._readInteger(ptrList + index * 4, 4).then(function (urlIndex) {
@@ -333,7 +332,6 @@ ZIMFile.prototype.setListings = function (listings) {
     // If we are in a legacy ZIM archive, we need to calculate the true article count (of entries in the A namespace)
     // This effectively emulates the v1 article pointerlist
     if (this.minorVersion === 0) {
-        // console.debug('ZIM DirListing version: 0 (legacy)', this);
         // Initiate a binary search for the first or last article
         var getArticleIndexByOrdinal = function (ordinal) {
             return util.binarySearch(0, that.entryCount, function (i) {