diff --git a/makeidx.py b/makeidx.py
new file mode 100644
index 0000000..f12a3ff
--- /dev/null
+++ b/makeidx.py
@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+
+"""Build the JSON with the list of presentions."""
+
+import os
+import re
+import logging
+import argparse
+import datetime
+import json
+
+DATA_BACKGROUND = re.compile(r"data-background='(.*?)'")
+PRES_TITLE = re.compile(r"<h1>(.*?)</h1>")
+
+
+def retrieve_presentation_info(filename):
+    """Open a file and try to retrieve the presentation information, like
+    background-image and title.
+    """
+    result = (None, None)
+    content = ''
+    with open(filename) as data:
+        content = data.read()
+
+    image = DATA_BACKGROUND.search(content)
+    title = PRES_TITLE.search(content)
+
+    if content and image and title:
+        logging.debug('Image for %s = %s', filename, image.group(1))
+        logging.debug('Title for %s = %s', filename, title.group(1))
+        result = (image.group(1), title.group(1))
+    return result
+
+
+def check_presentations(file_list):
+    """Check if the any of the files in the file list are presentations."""
+    result = []
+    for filename in file_list:
+        if not filename.endswith('.html'):
+            # presentations are HTML only
+            continue
+
+        (image, title) = retrieve_presentation_info(filename)
+        if image and title:
+            stat_info = os.stat(filename)
+            date = datetime.datetime.fromtimestamp(stat_info.st_mtime)
+            logging.debug('Modified date = %s', date)
+
+            result.append({'title': title,
+                           'image': image,
+                           'changed': date.strftime('%Y-%m-%d %H:%M:%S')})
+    return result
+
+
+def main():
+    """Main function."""
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-d', '--debug',
+                        action='store_const',
+                        dest='debug',
+                        default=False,
+                        const=True,
+                        help='Enable debugging messages')
+    args = parser.parse_args()
+
+    level = logging.INFO
+    if args.debug:
+        level = logging.DEBUG
+    logging.basicConfig(level=level)
+
+    for (root, _, files) in os.walk('.'):
+        if not root == '.':
+            # only files in the current directly will be checked
+            continue
+
+        content = check_presentations(files)
+        with open('index.json', 'w') as output:
+            output.write(json.dumps(content))
+
+    return
+
+
+if __name__ == "__main__":
+    main()