diff --git a/htmx/README.md b/htmx/README.md
new file mode 100644
index 0000000..c029605
--- /dev/null
+++ b/htmx/README.md
@@ -0,0 +1,26 @@
+This is a demo project for htmx, flask and babel, so this readme contains
+mostly random notes about its construction and maintenance.
+
+Localization
+============
+
+I followed the tutorial at https://phrase.com/blog/posts/python-localization-flask-applications/
+
+To extract messages, use
+
+```
+pybabel extract -F babel.cfg -o messages.pot .
+```
+
+The following creates a new translation file and may be a bad idea if you
+already have one:
+
+```
+pybabel init -i messages.pot -d translations -l de
+```
+
+Compile the translation file(s):
+
+```
+pybabel compile -d translations
+```
diff --git a/htmx/app.py b/htmx/app.py
new file mode 100644
index 0000000..57ed5b5
--- /dev/null
+++ b/htmx/app.py
@@ -0,0 +1,197 @@
+import logging
+import uuid
+import psycopg2
+import psycopg2.extras
+
+from flask import Flask, request, render_template, render_template_string, session, g
+from flask_babel import Babel, _
+
+logging.basicConfig(format="%(asctime)s %(levelname)s %(name)s %(lineno)d | %(message)s", level=logging.DEBUG)
+
+app = Flask(__name__)
+babel = Babel(app)
+app.secret_key = b"1234" # XXX - Should be in config (not in source, but stable across restarts)
+
+log = logging.getLogger(__name__)
+
+# Routes
+@app.route("/")
+def home():
+    log.info("in home")
+    app.logger.info("in home (via app.logger)")
+    log.info("greeting = %s", _("hello"))
+    user_public_id = None
+    if "uuid" not in session:
+        session["uuid"], user_public_id = new_user()
+    if not user_public_id:
+        csr = get_cursor()
+        csr.execute("select * from users where uuid = %s", (session["uuid"],))
+        user_public_id = csr.fetchone().public_id # Can this fail?
+
+    log.info("session = %s", session)
+    return render_template("home.html", public_id=user_public_id)
+
+@app.route("/entry_form", methods=["POST"])
+def entry_form():
+    log.info("session = %s", session)
+    user_uuid = session["uuid"]
+    log.info("user_uuid = %s", user_uuid)
+    csr = get_cursor()
+    csr.execute(
+        "select * from country_names natural join countries where lang=%s order by population desc",
+        (get_locale(),))
+    f = ""
+    for r in csr.fetchall():
+        csr.execute(
+            "select * from entries where uuid = %s and country = %s",
+            (user_uuid, r.code,))
+        f += render_template("entry_row.html", code=r.code, name=r.name, entries=csr.fetchall())
+    return f
+
+@app.route("/update_entries", methods=["POST"])
+def update_entries():
+    csr = get_cursor()
+    log.debug(request.form)
+    csr = get_cursor()
+    r = ""
+    for k, v in request.form.items():
+        (band, code, id) = k.split("_")
+        if id == "new":
+            csr.execute(
+                "insert into entries(country, uuid, band) values(%s, %s, %s) returning id",
+                (code, session["uuid"], v,))
+            id = csr.fetchone().id
+            extra = render_template_string(
+                        """<input name="band_{{code}}_new" hx-trigger="change" hx-post="/update_entries" hx-swap="outerHTML" autofocus>""",
+                        code=code)
+        else:
+            csr.execute(
+                "update entries set band = %s where id = %s and uuid = %s",
+                (v, id, session["uuid"],))
+            extra = ""
+        r += render_template_string(
+                    """<input name="band_{{code}}_{{id}}" value="{{band}}" hx-trigger="change" hx-post="/update_entries" hx-swap="outerHTML">""",
+                    code=code, id=id, band=v)
+        r += extra
+    return r
+
+@app.route("/result/<public_id>")
+def result(public_id):
+
+    lang = get_locale()
+    with get_dict_cursor() as csr:
+        csr.execute(
+                """
+                select country, name,
+                       band,
+                       count(*) as total,
+                       count(*) filter(where public_id = %s) as by_user
+                from entries e
+                    join countries c on c.code = e.country
+                    join country_names cn on e.country = cn.code and cn.lang = %s
+                    join users u using (uuid)
+                group by country, name, population, band
+                order by population desc, name, band
+                """,
+                (public_id, lang,))
+        country_stats = []
+        for r in csr:
+            if not country_stats or country_stats[-1]["code"] != r["country"]:
+                country_stats.append({"code": r["country"],
+                              "name": r["name"],
+                              "bands": []})
+            country_stats[-1]["bands"].append({"name": r["band"],
+                                       "total_count": r["total"],
+                                       "by_user": bool(r["by_user"])})
+
+        stats = { "countries": country_stats }
+        csr.execute(
+                """
+                with a as (
+                    select public_id, count(distinct(country)) as c
+                    from entries join users using (uuid)
+                    group by 1)
+                select public_id, c, rank() over (order by c desc) from a;
+                """
+        )
+        for r in csr:
+            if r["public_id"] == public_id:
+                stats["country_rank"] = r["rank"]
+                stats["country_count"] = r["c"]
+        stats["user_count"] = csr.rowcount
+
+        csr.execute(
+                """
+                with a as (
+                    select public_id, count(*) as c
+                    from entries join users using (uuid)
+                    group by 1)
+                select public_id, c, rank() over (order by c desc) from a;
+                """
+        )
+        for r in csr:
+            if r["public_id"] == public_id:
+                # XXX - clobbering previous results?
+                stats["band_rank"] = r["rank"]
+                stats["band_count"] = r["c"]
+
+    ask_mail = session["uuid"].endswith(public_id)
+    log.debug("uuid = %s, public_id=%s, ask_mail=%s", session["uuid"], public_id, ask_mail)
+    return render_template("result.html", public_id=public_id, stats=stats, ask_mail=ask_mail)
+
+@app.route("/add-email", methods=["POST"])
+def add_email():
+    csr = get_cursor()
+    csr.execute("update users set email=%s where uuid = %s", (request.form["email"], session["uuid"],))
+    if csr.rowcount:
+        return render_template_string(_("Saved. Expect mail at {{email}}"),
+                                      email=request.form["email"])
+    else:
+        return _("<span>You don't exist. Go away!</span>")
+
+# Middleware
+
+@babel.localeselector
+def get_locale():
+    lang = request.accept_languages.best_match(["de", "en"])
+    log.info("get_locale: best language is %s", lang)
+    return lang
+
+# Helpers
+
+def get_dict_cursor():
+    db = get_db()
+    csr = db.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
+    return csr
+
+def get_cursor():
+    db = get_db()
+    csr = db.cursor(cursor_factory=psycopg2.extras.NamedTupleCursor)
+    return csr
+
+def get_db():
+    if "db" not in g:
+        g.db = psycopg2.connect("dbname=internationale")
+    return g.db
+
+@app.teardown_appcontext
+def teardown_db(exception):
+    log.info("in teardown_db: exception = %s", exception)
+    db = g.pop('db', None)
+    if db is not None:
+        if not exception:
+            try:
+                db.commit()
+            except:
+                pass
+        db.rollback()
+        db.close()
+
+def new_user():
+    user_uuid = str(uuid.uuid4())
+    user_public_id = user_uuid[-12:]
+    csr = get_cursor()
+    csr.execute("insert into users(uuid, public_id) values(%s, %s)", (user_uuid, user_public_id,))
+    return user_uuid, user_public_id
+
+# vim: tw=99
diff --git a/htmx/babel.cfg b/htmx/babel.cfg
new file mode 100644
index 0000000..f0234b3
--- /dev/null
+++ b/htmx/babel.cfg
@@ -0,0 +1,3 @@
+[python: **.py]
+[jinja2: **/templates/**.html]
+extensions=jinja2.ext.autoescape,jinja2.ext.with_
diff --git a/htmx/messages.pot b/htmx/messages.pot
new file mode 100644
index 0000000..7da1d0c
--- /dev/null
+++ b/htmx/messages.pot
@@ -0,0 +1,65 @@
+# Translations template for PROJECT.
+# Copyright (C) 2022 ORGANIZATION
+# This file is distributed under the same license as the PROJECT project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2022.
+#
+#, fuzzy
+msgid ""
+msgstr ""
+"Project-Id-Version: PROJECT VERSION\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2022-03-20 23:24+0100\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language-Team: LANGUAGE <LL@li.org>\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 2.9.1\n"
+
+#: app.py:22
+msgid "hello"
+msgstr ""
+
+#: app.py:147
+msgid "Saved. Expect mail at {{email}}"
+msgstr ""
+
+#: app.py:150
+msgid "<span>You don't exist. Go away!</span>"
+msgstr ""
+
+#: templates/home.html:6 templates/result.html:6
+msgid "The Musical Internatiionale"
+msgstr ""
+
+#: templates/home.html:20
+msgid ""
+"All the countries in the world — which bands or solo musicians from these"
+" countries do you know?"
+msgstr ""
+
+#: templates/home.html:32
+msgid "Show"
+msgstr ""
+
+#: templates/result.html:15
+#, python-format
+msgid ""
+"You have entered %(band_count)s bands or artists from %(country_count)s "
+"countries."
+msgstr ""
+
+#: templates/result.html:18
+#, python-format
+msgid ""
+"This puts you at rank %(band_rank)s and %(country_rank)s of "
+"%(user_count)s, respectively."
+msgstr ""
+
+#: templates/result.html:37
+msgid ""
+"You can leave your email address here if you want to be informed about "
+"future developments"
+msgstr ""
+
diff --git a/htmx/requirements.txt b/htmx/requirements.txt
new file mode 100644
index 0000000..d05211a
--- /dev/null
+++ b/htmx/requirements.txt
@@ -0,0 +1,2 @@
+Flask
+Flask-Babel
diff --git a/htmx/static/MontserratAlternates-Bold.ttf b/htmx/static/MontserratAlternates-Bold.ttf
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diff --git a/htmx/static/MontserratAlternates-Light.ttf b/htmx/static/MontserratAlternates-Light.ttf
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diff --git a/htmx/static/MontserratAlternates-LightItalic.ttf b/htmx/static/MontserratAlternates-LightItalic.ttf
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diff --git a/htmx/static/MontserratAlternates-Medium.ttf b/htmx/static/MontserratAlternates-Medium.ttf
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diff --git a/htmx/static/MontserratAlternates-MediumItalic.ttf b/htmx/static/MontserratAlternates-MediumItalic.ttf
new file mode 100644
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diff --git a/htmx/static/MontserratAlternates-Regular.ttf b/htmx/static/MontserratAlternates-Regular.ttf
new file mode 100644
index 0000000..d3163e7
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diff --git a/htmx/static/guitar.png b/htmx/static/guitar.png
new file mode 100644
index 0000000..882c2cd
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diff --git a/htmx/static/style.css b/htmx/static/style.css
new file mode 100644
index 0000000..f3ada21
--- /dev/null
+++ b/htmx/static/style.css
@@ -0,0 +1,205 @@
+cite {
+  display: block;
+}
+
+cite::before {
+  content: "—";
+}
+
+th {
+  text-align: right;
+}
+
+main {
+  display: grid;
+}
+
+#the-quote {
+  grid-column: 2;
+}
+
+.intro {
+  grid-column: 1;
+  grid-row: 1;
+}
+
+#country-list {
+  grid-column: 1 / 3;
+  grid-row: 2;
+  justify-self: left;
+}
+
+#permalink {
+    grid-column: 2;
+    grid-row: 1;
+    margin-left: auto;
+}
+
+#summary {
+    grid-column: 1;
+    grid-row: 1;
+}
+
+@media (max-width: 40rem) {
+    #the-quote {
+      grid-column: 2;
+    }
+
+    .intro {
+      grid-column: 1 / 3;
+      grid-row: 2;
+    }
+
+    #country-list {
+      grid-column: 1 / 3;
+      grid-row: 3;
+    }
+
+    #permalink {
+        grid-column: 2;
+        grid-row: 1;
+        margin-left: auto;
+    }
+
+    #summary {
+        grid-column: 1 /3;
+        grid-row: 2;
+    }
+}
+
+.intro {
+    margin: 3em;
+    font-family: MontserratAlternates;
+    font-weight: 300;
+    font-size: 1.2rem;
+    line-height: 1.7rem;
+}
+
+#country-list input {
+  margin: 0.2em 0.5em;
+}
+
+input:focus {
+  box-shadow: 0 0 0.2em 0.2em hsl(240 100% 70%);
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-Light.ttf);
+    font-weight: 300;
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-Regular.ttf);
+    font-weight: 400;
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-Medium.ttf);
+    font-weight: 500;
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-Bold.ttf);
+    font-weight: 700;
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-LightItalic.ttf);
+    font-weight: 300;
+    font-style: italic;
+}
+
+@font-face {
+    font-family: MontserratAlternates;
+    src: url(MontserratAlternates-MediumItalic.ttf);
+    font-weight: 500;
+    font-style: italic;
+}
+
+th {
+    vertical-align: baseline;
+    font-family: MontserratAlternates;
+    font-weight: 400;
+    font-color: #444;
+}
+
+td {
+  vertical-align: baseline;
+}
+
+body {
+    background-image: url("guitar.png");
+    background-size: contain;
+    background-repeat: no-repeat;
+    background-attachment: fixed;
+    text-shadow: 0 0 1.0em #FFFFFF,
+                 0 0 0.2em #FFFFFF;
+    font-family: MontserratAlternates;
+    font-weight: 300;
+    line-height: 1.4;
+}
+
+.band {
+    font-family: MontserratAlternates;
+    font-weight: 300;
+    white-space: nowrap;
+}
+.band.by_user {
+    font-weight: 500;
+    font-style: italic;
+}
+
+table {
+    border-spacing: 1em 0.3em;
+}
+
+#permalink a {
+    text-decoration: none;
+    color: #444;
+    padding: 0.5em;
+    border: 1px dotted black;
+}
+
+#summary {
+    margin-left: 3em;
+}
+
+.buttonrow {
+    display: flex;
+    justify-content: space-around;
+}
+
+.btn {
+    margin-top: 2em;
+    margin-left: auto;
+    margin-right: auto;
+    text-decoration: none;
+    color: #000;
+    border: solid 1px #888;
+    background-color: #CCD;
+    padding: 1em;
+    border-radius: 0.5em;
+    box-shadow: 0 0 0.3em 0.2em hsla(0, 0%, 70%, 0.5);
+    font-weight: 700;
+    display: inline-block;
+}
+
+.btn:focus, .btn:hover {
+    background-color: #DDF;
+    border: solid 1px #88F;
+    box-shadow: 0 0 0.3em 0.4em hsla(240, 30%, 70%, 0.5);
+}
+
+p {
+    background-color: #FFFFFF80;
+}
+
+/*
+  vim: sw=4
+ */
+
diff --git a/htmx/templates/entry_row.html b/htmx/templates/entry_row.html
new file mode 100644
index 0000000..10e08de
--- /dev/null
+++ b/htmx/templates/entry_row.html
@@ -0,0 +1,11 @@
+<tr>
+  <th>
+    {{name}}
+  </th>
+  <td>
+    {% for e in entries %}
+      <input name="band_{{code}}_{{e.id}}" value="{{e.band}}" hx-trigger="change" hx-post="/update_entries" hx-swap="outerHTML">
+    {% endfor %}
+    <input name="band_{{code}}_new" hx-trigger="change" hx-post="/update_entries" hx-swap="outerHTML">
+  </td>
+</tr>
diff --git a/htmx/templates/home.html b/htmx/templates/home.html
new file mode 100644
index 0000000..649484d
--- /dev/null
+++ b/htmx/templates/home.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="UTF-8">
+    <title>
+      {{ _("The Musical Internatiionale") }}
+    </title>
+    <script src='https://unpkg.com/htmx.org@1.7.0'></script>
+    <link rel="stylesheet" href="/static/style.css">
+  </head>
+  <body>
+    <main>
+      <blockquote id="the-quote">
+        I don't need a rationale<br/>
+        to sing the Internationale
+        <cite>
+          They might be giants
+        </cite>
+      </blockquote>
+      <div class="intro">{{ _("All the countries in the world — which bands or solo musicians from these countries do you know?") }}</div>
+      <table id="country-list">
+        <tbody hx-post="/entry_form" hx-trigger="load">
+
+        </tbody>
+        <tfoot>
+          <tr>
+            <td>
+
+            </td>
+            <td>
+              <a href="/result/{{ public_id }}" class="btn">
+                {{ _("Show") }}
+              </a>
+            </td>
+          </tr>
+        </tfoot>
+      </table>
+    </main>
+  </body>
+</html>
+
diff --git a/htmx/templates/result.html b/htmx/templates/result.html
new file mode 100644
index 0000000..7e787bd
--- /dev/null
+++ b/htmx/templates/result.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="UTF-8">
+    <title>
+      {{ _("The Musical Internatiionale") }}
+    </title>
+    <script src='https://unpkg.com/htmx.org@1.7.0'></script>
+    <link rel="stylesheet" href="/static/style.css">
+  </head>
+  <body>
+    <main>
+      <section>
+        <p>
+          {{_("You have entered %(band_count)s bands or artists from %(country_count)s countries.", band_count=stats.band_count, country_count=stats.country_count)}}
+        </p>
+        <p>
+          {{_("This puts you at rank %(band_rank)s and %(country_rank)s of %(user_count)s, respectively.", band_rank=stats.band_rank, country_rank=stats.country_rank, user_count=stats.user_count)}}
+        </p>
+        <table>
+          {% for c in stats.countries %}
+          <tr>
+            <th>
+              {{ c.name }}
+            </th>
+            <td>
+              {% for b in c.bands %}
+                <span class="band {%if b.by_user %}by_user{%endif%}">{{b.name}}</span>{%if not loop.last%},{%endif%}
+              {% endfor %}
+            </td>
+          </tr>
+          {% endfor %}
+        </table>
+      </section>
+      {% if ask_mail %}
+        <p>
+          {{_("You can leave your email address here if you want to be informed about future developments")}}
+          <br>
+          <input hx-post="/add-email" name="email" hx-swap="outerHTML">
+        </p>
+      {% endif %}
+    </main>
+  </body>
+</html>
diff --git a/htmx/translations/de/LC_MESSAGES/messages.mo b/htmx/translations/de/LC_MESSAGES/messages.mo
new file mode 100644
index 0000000..2826bad
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diff --git a/htmx/translations/de/LC_MESSAGES/messages.po b/htmx/translations/de/LC_MESSAGES/messages.po
new file mode 100644
index 0000000..cf57a26
--- /dev/null
+++ b/htmx/translations/de/LC_MESSAGES/messages.po
@@ -0,0 +1,68 @@
+# German translations for PROJECT.
+# Copyright (C) 2022 ORGANIZATION
+# This file is distributed under the same license as the PROJECT project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2022.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: PROJECT VERSION\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2022-02-27 01:46+0100\n"
+"PO-Revision-Date: 2022-02-27 01:47+0100\n"
+"Last-Translator: Peter J. Holzer <hjp@hjp.at>\n"
+"Language: de\n"
+"Language-Team: de <LL@li.org>\n"
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 2.9.1\n"
+
+#: app.py:23
+msgid "hello"
+msgstr "Hallo"
+
+#: app.py:147
+msgid "Saved. Expect mail at {{email}}"
+msgstr "Gespeichert. Du wirst Mail an {{email}} bekommen."
+
+#: app.py:150
+msgid "<span>You don't exist. Go away!</span>"
+msgstr "Du existierst nicht. Verschwinde!"
+
+#: templates/home.html:6
+msgid "The Musical Internatiionale"
+msgstr "Die Musik-Internationale"
+
+#: templates/home.html:21
+msgid ""
+"All the countries in the world — which bands or solo musicians from these"
+" countries do you know?"
+msgstr "Alle Länder dieser Erde — welche Bands oder Solo-Musiker aus diesen Ländern kennst Du?"
+
+#: templates/home.html:24
+msgid "Show"
+msgstr "Aufdecken"
+
+#: templates/result.html:15
+#, python-format
+msgid ""
+"You have entered %(band_count)s bands or artists from %(country_count)s "
+"countries."
+msgstr "Du hast %(band_count)s Bands oder Solo-Musiker aus "
+"%(country_count)s Ländern eingegeben."
+
+#: templates/result.html:18
+#, python-format
+msgid ""
+"This puts you at rank %(band_rank)s and %(country_rank)s of "
+"%(user_count)s, respectively."
+msgstr "Damit bist Du an %(band_rank)s. bzw. %(country_rank)s. Stelle von %(user_count)s."
+
+#: templates/result.html:37
+msgid ""
+"You can leave your email address here if you want to be informed about "
+"future developments"
+msgstr "Wenn Du über zukünftige Entwicklungen informiert werden willst, "
+"kannst Du Deine Mail-Adresse hier hinterlassen:"
+