diff --git a/history-script.py b/history-script.py
new file mode 100644
index 0000000..c2de6a5
--- /dev/null
+++ b/history-script.py
@@ -0,0 +1,73 @@
+import os, sys, json
+import sqlite3
+
+database = 'history.sqlite3'
+
+def select_keys(data, key_list):
+    return [data[key] for key in key_list]
+
+def keyfn(addon):
+    return (addon['source'], addon['source-id'])
+
+def mkidx(addon_list):
+    return {keyfn(addon):addon for addon in addon_list}
+
+def popularity_data(curr_addon, prev_addon):
+    num = curr_addon['download-count']
+    prev_num = prev_addon.get('download-count', num)
+    diff = num - prev_num
+    return {
+        'count': num,
+        'count_difference': diff
+    }
+
+def db_connection():
+    return sqlite3.connect(database)
+
+def insert(db, addon):
+    sql = """INSERT INTO addon 
+        (timestamp, source, source_id, name, count, count_difference)
+    VALUES
+        (?,?,?,?,?,?);"""
+    data = select_keys(addon, ['timestamp', 'source', 'source-id', 'name', 'count', 'count_difference'])
+    db.execute(sql, tuple(data))
+
+def init_db():
+    db = sqlite3.connect(database)
+    sql = """
+        CREATE TABLE addon(
+            timestamp DATETIME NOT NULL,
+            source TEXT NOT NULL,
+            source_id INTEGER NOT NULL,
+            name TEXT NOT NULL,
+            count INTEGER NOT NULL,
+            count_difference INTEGER NOT NULL,
+            
+            PRIMARY KEY (timestamp, source, source_id)
+        );"""
+    db.execute(sql)
+    db.commit()
+
+def main(timestamp, curr_catalogue_fname, prev_catalogue_fname):
+    curr_catalogue = json.load(open(curr_catalogue_fname, 'r'))
+    prev_catalogue = {'addon-summary-list': []}
+    # previous catalogue won't exist on first call to script.
+    if os.path.exists(prev_catalogue_fname):
+        prev_catalogue = json.load(open(prev_catalogue_fname, 'r'))
+
+    addon_list = curr_catalogue['addon-summary-list']
+    prev_addon_idx = mkidx(prev_catalogue['addon-summary-list'])
+    
+    if not os.path.exists(database):
+        init_db()
+    
+    db = db_connection()
+    for addon in addon_list:
+        addon_key = keyfn(addon)
+        addon.update(popularity_data(addon, prev_addon_idx.get(addon_key, {})))
+        addon['timestamp'] = timestamp
+        insert(db, addon)
+    db.commit()
+
+if __name__ == '__main__':
+    main(*sys.argv[1:4])
diff --git a/history-script.sh b/history-script.sh
new file mode 100755
index 0000000..6b5d559
--- /dev/null
+++ b/history-script.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+# goes through git history, oldest to newest, and creates a database of popularity data for addons overtime
+set -e
+
+catalogue=${1:-"full-catalogue.json"}
+
+# clean up from any previous runs
+git checkout master
+rm -f "*.json.prev" history.sqlite3
+
+# list of commit references, oldest to newest
+ref_list=$(git log  --reverse | grep '^commit' | cut -c 8-)
+
+# checkout ref, call script with ref, timestamp and catalogue files
+for ref in $ref_list; do
+    git checkout "$ref" --quiet
+    timestamp=$(TZ=UTC git --no-pager log -1 --format=%cd --date=iso-strict-local)
+    echo "$timestamp: $ref"
+    python history-script.py "$timestamp" "$catalogue" "$catalogue.prev"
+    # so the next iteration reads from previous iteration's catalogue
+    cp "$catalogue" "$catalogue.prev"
+    echo "---"
+done
+
+sqlite3 history.sqlite3 "select sum(count_difference) as pop, source, source_id as 'source-id', name from addon where source = 'curseforge' group by source, source_id, name order by pop desc limit 50;" -json > most-popular-curseforge.json
+echo "wrote most-popular-curseforge.json"
+
+sqlite3 history.sqlite3 "select sum(count_difference) as pop, source, source_id as 'source-id', name from addon where source = 'wowinterface' group by source, source_id, name order by pop desc limit 50;" -json > most-popular-wowinterface.json
+echo "wrote most-popular-wowinterface.json"
+
+rm -f "$catalogue.prev"
+git checkout master