diff --git a/src/_h5ai/backend/php/class-bootstrap.php b/src/_h5ai/backend/php/class-bootstrap.php
index 2bb458be..d47a8275 100644
--- a/src/_h5ai/backend/php/class-bootstrap.php
+++ b/src/_h5ai/backend/php/class-bootstrap.php
@@ -21,9 +21,11 @@ class Bootstrap {
             (new Api($context))->apply();
         } else if ($context->is_info_request()) {
             $public_href = $setup->get('PUBLIC_HREF');
+            $x_head_tags = $context->get_x_head_html();
             require __DIR__ . '/pages/info.php';
         } else {
             $public_href = $setup->get('PUBLIC_HREF');
+            $x_head_tags = $context->get_x_head_html();
             $fallback_html = (new Fallback($context))->get_html();
             require __DIR__ . '/pages/index.php';
         }
diff --git a/src/_h5ai/backend/php/core/class-context.php b/src/_h5ai/backend/php/core/class-context.php
index 242975b2..2383a605 100644
--- a/src/_h5ai/backend/php/core/class-context.php
+++ b/src/_h5ai/backend/php/core/class-context.php
@@ -17,7 +17,7 @@ class Context {
         $this->request = $request;
         $this->setup = $setup;
 
-        $this->options = Util::load_commented_json($this->setup->get('APP_PATH') . '/conf/options.json');
+        $this->options = Json::load($this->setup->get('APP_PATH') . '/conf/options.json');
 
         $this->passhash = $this->query_option('passhash', '');
         $this->options['hasCustomPasshash'] = strcasecmp($this->passhash, Context::$DEFAULT_PASSHASH) !== 0;
@@ -51,7 +51,7 @@ class Context {
 
     public function get_types() {
 
-        return Util::load_commented_json($this->setup->get('APP_PATH') . '/conf/types.json');
+        return Json::load($this->setup->get('APP_PATH') . '/conf/types.json');
     }
 
     public function login_admin($pass) {
@@ -222,7 +222,7 @@ class Context {
             if ($dir = opendir($l10n_path)) {
                 while (($file = readdir($dir)) !== false) {
                     if (Util::ends_with($file, '.json')) {
-                        $translations = Util::load_commented_json($l10n_path . '/' . $file);
+                        $translations = Json::load($l10n_path . '/' . $file);
                         $langs[basename($file, '.json')] = $translations['lang'];
                     }
                 }
@@ -239,7 +239,7 @@ class Context {
 
         foreach ($iso_codes as $iso_code) {
             $file = $this->setup->get('APP_PATH') . '/conf/l10n/' . $iso_code . '.json';
-            $results[$iso_code] = Util::load_commented_json($file);
+            $results[$iso_code] = Json::load($file);
             $results[$iso_code]['isoCode'] = $iso_code;
         }
 
@@ -257,4 +257,31 @@ class Context {
 
         return $hrefs;
     }
+
+    private function prefix_x_head_href($href) {
+
+        if (preg_match('@^(https?://|/)@i', $href)) {
+            return $href;
+        }
+
+        return $this->setup->get('PUBLIC_HREF') . 'ext/' . $href;
+    }
+
+    public function get_x_head_html() {
+
+        $scripts = $this->query_option('resources.scripts', []);
+        $styles = $this->query_option('resources.styles', []);
+
+        $tags = '';
+
+        foreach ($styles as $href) {
+            $tags .= '<link rel="stylesheet" href="' . $this->prefix_x_head_href($href) . '" class="x-head">';
+        }
+
+        foreach ($scripts as $href) {
+            $tags .= '<script src="' . $this->prefix_x_head_href($href) . '" class="x-head"></script>';
+        }
+
+        return $tags;
+    }
 }
diff --git a/src/_h5ai/backend/php/core/class-json.php b/src/_h5ai/backend/php/core/class-json.php
new file mode 100644
index 00000000..06626f57
--- /dev/null
+++ b/src/_h5ai/backend/php/core/class-json.php
@@ -0,0 +1,71 @@
+<?php
+
+class Json {
+
+    const SINGLE = 1;
+    const MULTI = 2;
+
+    public static function load($path) {
+
+        if (!is_readable($path)) {
+            return [];
+        }
+
+        $json = file_get_contents($path);
+        return Json::decode($json);
+    }
+
+    public static function save($path, $obj) {
+
+        $json = json_encode($obj);
+        return file_put_contents($path, $json) !== false;
+    }
+
+    public static function decode($json) {
+
+        $json = Json::strip($json);
+        return json_decode($json, true);
+    }
+
+    public static function strip($commented_json) {
+
+        $insideString = false;
+        $insideComment = false;
+        $json = '';
+
+        for ($i = 0; $i < strlen($commented_json); $i += 1) {
+
+            $char = $commented_json[$i];
+            $charchar = $char . @$commented_json[$i + 1];
+            $prevChar = @$commented_json[$i - 1];
+
+            if (!$insideComment && $char === '"' && $prevChar !== "\\") {
+                $insideString = !$insideString;
+            }
+
+            if ($insideString) {
+                $json .= $char;
+            } else if (!$insideComment && $charchar === '//') {
+                $insideComment = Json::SINGLE;
+                $i += 1;
+            } else if (!$insideComment && $charchar === '/*') {
+                $insideComment = Json::MULTI;
+                $i += 1;
+            } else if (!$insideComment) {
+                $json .= $char;
+            } else if ($insideComment === Json::SINGLE && $charchar === "\r\n") {
+                $insideComment = false;
+                $json .= $charchar;
+                $i += 1;
+            } else if ($insideComment === Json::SINGLE && $char === "\n") {
+                $insideComment = false;
+                $json .= $char;
+            } else if ($insideComment === Json::MULTI && $charchar === '*/') {
+                $insideComment = false;
+                $i += 1;
+            }
+        }
+
+        return $json;
+    }
+}
diff --git a/src/_h5ai/backend/php/core/class-setup.php b/src/_h5ai/backend/php/core/class-setup.php
index affec3f1..5bcef6cc 100644
--- a/src/_h5ai/backend/php/core/class-setup.php
+++ b/src/_h5ai/backend/php/core/class-setup.php
@@ -125,7 +125,7 @@ class Setup {
 
         $cmds_cache_path = Util::normalize_path($this->get('CACHE_PRV_PATH') . '/cmds.json', false);
 
-        $cmds = Util::load_commented_json($cmds_cache_path);
+        $cmds = Json::load($cmds_cache_path);
         if (sizeof($cmds) === 0 || $this->refresh) {
             $cmds['command'] = Util::exec_0('command -v command');
             $cmds['which'] = Util::exec_0('which which');
@@ -141,7 +141,7 @@ class Setup {
                 $cmds[$c] = ($cmd !== false) && Util::exec_0($cmd . ' ' . $c);
             }
 
-            Util::save_json($cmds_cache_path, $cmds);
+            Json::save($cmds_cache_path, $cmds);
         }
         foreach ($cmds as $c => $has) {
             $this->set('HAS_CMD_' . strtoupper($c), $has);
diff --git a/src/_h5ai/backend/php/core/class-util.php b/src/_h5ai/backend/php/core/class-util.php
index c75c497e..35c0940c 100644
--- a/src/_h5ai/backend/php/core/class-util.php
+++ b/src/_h5ai/backend/php/core/class-util.php
@@ -61,26 +61,6 @@ class Util {
         return Util::RE_DELIMITER . str_replace(Util::RE_DELIMITER, '\\' . Util::RE_DELIMITER, $pattern) . Util::RE_DELIMITER;
     }
 
-    public static function load_commented_json($path) {
-
-        if (!file_exists($path)) {
-            return [];
-        }
-
-        $content = file_get_contents($path);
-
-        // remove comments to get pure json
-        $content = preg_replace("/\/\*.*?\*\/|\/\/.*?(\n|$)/s", '', $content);
-
-        return json_decode($content, true);
-    }
-
-    public static function save_json($path, $obj) {
-
-        $json = json_encode($obj);
-        return file_put_contents($path, $json) !== false;
-    }
-
     public static function passthru_cmd($cmd) {
 
         $rc = null;
diff --git a/src/_h5ai/backend/php/pages/page.tpl.jade b/src/_h5ai/backend/php/pages/page.tpl.jade
index f0745448..3f37e5aa 100644
--- a/src/_h5ai/backend/php/pages/page.tpl.jade
+++ b/src/_h5ai/backend/php/pages/page.tpl.jade
@@ -1,5 +1,3 @@
-- var public_href = '<?= $public_href; ?>'
-
 block init
 
 <?php header('Content-type: text/html;charset=utf-8'); ?>
@@ -13,11 +11,11 @@ head
     title #{title}
     meta(name='description', content='#{title}')
     meta(name='viewport', content='width=device-width, initial-scale=1')
-    link(rel='shortcut icon', href!='#{public_href}images/favicon/favicon-16-32.ico')
-    link(rel='apple-touch-icon-precomposed', type='image/png', href!='#{public_href}images/favicon/favicon-152.png')
-    link(rel='stylesheet', href='//fonts.googleapis.com/css?family=Roboto:300,400,700')
-    link(rel='stylesheet', href!='#{public_href}css/styles.css')
-    script(src!='#{public_href}js/scripts.js', data-module='#{module}')
+    link(rel='shortcut icon', href!='<?= $public_href; ?>images/favicon/favicon-16-32.ico')
+    link(rel='apple-touch-icon-precomposed', type='image/png', href!='<?= $public_href; ?>images/favicon/favicon-152.png')
+    link(rel='stylesheet', href!='<?= $public_href; ?>css/styles.css')
+    script(src!='<?= $public_href; ?>js/scripts.js', data-module='#{module}')
+    <?= $x_head_tags; ?>
 
 body#root(class='#{module}')
 
diff --git a/src/_h5ai/conf/options.json b/src/_h5ai/conf/options.json
index e8f7d74d..61202b72 100644
--- a/src/_h5ai/conf/options.json
+++ b/src/_h5ai/conf/options.json
@@ -16,6 +16,25 @@ Options
 
 
 
+    /*
+    Resources.
+
+    Additional script and style tags added to all pages. Paths not beginning
+    with "http://", "https://" or "/" will be looked up relative to
+    "_h5ai/public/ext/" (no check for existence).
+
+    - scripts: array of strings
+    - styles: array of strings
+    */
+    "resources": {
+        "scripts": [],
+        "styles": [
+            "//fonts.googleapis.com/css?family=Roboto:300,400,700"
+        ]
+    },
+
+
+
     /*
     General view options.