diff --git a/app/lib/babycode.py b/app/lib/babycode.py
index 110c5a7..db00866 100644
--- a/app/lib/babycode.py
+++ b/app/lib/babycode.py
@@ -6,7 +6,7 @@ from pygments.lexers import get_lexer_by_name
 from pygments.util import ClassNotFound as PygmentsClassNotFound
 import re
 
-BABYCODE_VERSION = 11
+BABYCODE_VERSION = 13
 
 
 class BabycodeError(Exception):
@@ -406,6 +406,13 @@ def tag_quote(children, attr):
 
     return f'<fieldset class="plank minimal no-shadow secondary-bg"><legend>{quotee}</legend><blockquote>{children}</blockquote></fieldset>'
 
+def tag_quote_rss(children, attr):
+    if attr:
+        quotee = f'Quoting: {attr.strip()}'
+        return f'<figure><blockquote>{children}</blockquote><figcaption>{quotee}</figcaption></figure>'
+    else:
+        return f'<blockquote>{children}</blockquote>'
+
 TAGS = {
     "b": lambda children, attr: f"<strong>{children}</strong>",
     "i": lambda children, attr: f"<em>{children}</em>",
@@ -462,6 +469,7 @@ RSS_TAGS = {
     'url': tag_url_rss,
     'spoiler': lambda children, attr: f'<details><summary>{attr or "Spoiler"} (click to reveal)</summary>{children}</details>',
     'code': tag_code_rss,
+    'quote': tag_quote_rss,
 
     'big': lambda children, attr: f'<span style="font-size: 1.2em">{children}</span>',
     'small': lambda children, attr: f'<small>{children}</small>'
diff --git a/app/routes/threads.py b/app/routes/threads.py
index 5a5f5cf..751726d 100644
--- a/app/routes/threads.py
+++ b/app/routes/threads.py
@@ -1,8 +1,10 @@
-from flask import Blueprint, redirect, url_for, render_template, request, abort
+from flask import Blueprint, redirect, url_for, render_template, request, abort, current_app
 from functools import wraps
+from app import cache
 from ..auth import login_required, get_active_user, is_logged_in
 from ..db import db
 from ..models import Threads, Posts, Topics, Users, Reactions, Subscriptions
+from ..lib.render_atom import render_atom_template
 from ..util import get_form_checkbox, time_now
 import math
 
@@ -70,9 +72,23 @@ def thread(thread_id, slug):
         posts=posts, page=page,
         page_count=page_count, topic=topic,
         started_by=started_by, topics=Topics.get_list(),
-        Reactions=Reactions, last_post=last_post
+        Reactions=Reactions, last_post=last_post,
+        __feedlink=url_for('.feed', thread_id=thread_id, _external=True),
+        __feedtitle=f'replies to {thread.title}',
         )
 
+@bp.get('/<int:thread_id>/feed.atom/')
+@cache.cached(timeout=5 * 60, unless=lambda: current_app.config['DEBUG'])
+def feed(thread_id):
+    thread = Threads.find({'id': thread_id})
+    if not thread:
+        abort(404)
+
+    topic = Topics.find({'id': thread.topic_id})
+    posts = thread.get_posts_rss()
+
+    return render_atom_template('threads/thread.atom', thread=thread, topic=topic, posts=posts)
+
 @bp.post('/<int:thread_id>/')
 @login_required
 def reply(thread_id):
@@ -195,10 +211,6 @@ def mark_read():
 
     return redirect(url_for('users.inbox', username=user.username))
 
-@bp.get('/<int:thread_id>/feed.atom/')
-def feed(thread_id):
-    return 'stub'
-
 @bp.get('/new/')
 @login_required
 def new():
diff --git a/app/routes/topics.py b/app/routes/topics.py
index 4476b58..7c42a7f 100644
--- a/app/routes/topics.py
+++ b/app/routes/topics.py
@@ -1,5 +1,6 @@
-from flask import Blueprint, redirect, url_for, render_template, request, session, abort
-
+from flask import Blueprint, redirect, url_for, render_template, request, session, abort, current_app
+from app import cache
+from ..lib.render_atom import render_atom_template
 from ..models import Topics, Threads, Subscriptions
 from ..auth import get_active_user
 import math
@@ -42,8 +43,20 @@ def topic(topic_id, slug):
             subscription = Subscriptions.find({'user_id': user.id, 'thread_id': thread['id']})
             if subscription:
                 subscriptions[thread['id']] = subscription.get_unread_count()
-    return render_template('topics/topic.html', topic=topic, threads=threads, sort_by=sort_by, page=page, page_count=page_count, subscriptions=subscriptions)
+    return render_template(
+        'topics/topic.html', topic=topic,
+        threads=threads, sort_by=sort_by,
+        page=page, page_count=page_count, subscriptions=subscriptions,
+        __feedlink=url_for('.feed', topic_id=topic_id, _external=True),
+        __feedtitle=f'latest threads in {topic.name}',
+    )
 
 @bp.get('/<int:topic_id>/feed.atom/')
+@cache.cached(timeout=5 * 60, unless=lambda: current_app.config['DEBUG'])
 def feed(topic_id):
-    return 'stub'
+    topic = Topics.find({'id': topic_id})
+    if not topic:
+        abort(404)
+
+    threads_list = topic.get_threads_with_op_rss()
+    return render_atom_template('topics/topic.atom', topic=topic, threads_list=threads_list)
diff --git a/app/templates/base.atom b/app/templates/base.atom
new file mode 100644
index 0000000..21aa7e1
--- /dev/null
+++ b/app/templates/base.atom
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+  {%- if self.title() -%}
+  <title>{%- block title -%}{%- endblock -%}</title>
+  {%- else -%}
+  <title>{{- config.SITE_NAME -}}</title>
+  {%- endif -%}
+  {%- if self.feed_updated() -%}
+  <updated>{%- block feed_updated -%}{%- endblock -%}</updated>
+  {%- else -%}
+  <updated>{{- get_time_now() | iso8601 -}}</updated>
+  {%- endif -%}
+  <id>{{- __current_page -}}</id>
+  <link rel="self" href="{{ __current_page }}" />
+  <link href="{%- block canonical_link -%}{%- endblock -%}" />
+  {%- if self.feed_author() -%}
+    <author>{%- block feed_author -%}{%- endblock -%}</author>
+    {%- endif -%}
+    {%- block content -%}{%- endblock -%}
+</feed>
diff --git a/app/templates/base.html b/app/templates/base.html
index 37f6c13..f413ab0 100644
--- a/app/templates/base.html
+++ b/app/templates/base.html
@@ -11,6 +11,9 @@
     {%- else -%}
     <title>{{ config.SITE_NAME }}</title>
     {%- endif -%}
+    {%- if __feedlink -%}
+    <link rel="alternate" type="application/atom+xml" href="{{ __feedlink }}" title="{{ __feedtitle }}">
+    {%- endif -%}
   </head>
   <body>
     <bitty-8 data-connect="/static/js/bits/progressive-enhancement.js"></bitty-8>
diff --git a/app/templates/common/macros.html b/app/templates/common/macros.html
index 0eabf79..e7be0ee 100644
--- a/app/templates/common/macros.html
+++ b/app/templates/common/macros.html
@@ -302,3 +302,7 @@
   <div class="sortable-item-inner {{full and 'full' or ''}}">{{ caller() }}</div>
 </li>
 {%- endmacro %}
+
+{% macro rss_html_content(html) -%}
+<content type="html">{{ html }}</content>
+{%- endmacro %}
diff --git a/app/templates/threads/thread.atom b/app/templates/threads/thread.atom
new file mode 100644
index 0000000..63772c8
--- /dev/null
+++ b/app/templates/threads/thread.atom
@@ -0,0 +1,20 @@
+{% from 'common/macros.html' import rss_html_content %}
+{%- extends 'base.atom' -%}
+{%- block title -%}replies to {{thread.title}}{%- endblock -%}
+{%- block canonical_link -%}{{ url_for('threads.thread_by_id', thread_id=thread.id, _external=true) }}{%- endblock -%}
+{%- block content -%}
+  {%- for post in posts -%}
+  {%- set post_url = get_post_url(post.id, _anchor=true, external=true) -%}
+  <entry>
+    <title>Re: {{ thread.title | escape }}</title>
+    <link href="{{ post_url }}"/>
+    <id>{{ post_url }}</id>
+    <updated>{{ post.edited_at | iso8601 }}</updated>
+    {{ rss_html_content(post.content_rss) }}
+    <author>
+      <name>{{ post.display_name | escape }} @{{ post.username }}</name>
+      <uri>{{ url_for('users.user_page', username=post.username, _external=true) }}</uri>
+    </author>
+  </entry>
+  {%- endfor -%}
+{%- endblock -%}
diff --git a/app/templates/topics/topic.atom b/app/templates/topics/topic.atom
new file mode 100644
index 0000000..208c322
--- /dev/null
+++ b/app/templates/topics/topic.atom
@@ -0,0 +1,21 @@
+{% from 'common/macros.html' import rss_html_content %}
+{%- extends 'base.atom' -%}
+{%- block title -%}latest threads in {{topic.name | escape}}{%- endblock -%}
+{%- block canonical_link -%}{{ url_for('topics.topic_by_id', topic_id=topic.id, _external=true) }}{%- endblock -%}
+{%- block content -%}
+  <subtitle>{{ topic.description | escape }}</subtitle>
+  {%- for thread in threads_list -%}
+    <entry>
+      <title>{{ thread.title | escape }}</title>
+      <link href="{{ url_for('threads.thread_by_id', thread_id=thread.id, _external=true) }}"/>
+      <link rel="replies" type="application/atom+xml" href="{{ url_for('threads.feed', thread_id=thread.id, _external=true) }}"/>
+      <id>{{ url_for('threads.thread_by_id', thread_id=thread.id, _external=true) }}</id>
+      {{ rss_html_content(thread.original_post_content) }}
+      <updated>{{ thread.created_at | iso8601 }}</updated>
+      <author>
+        <name>{{ thread.started_by_display_name | escape }} @{{ thread.started_by }}</name>
+        <uri>{{ url_for('users.user_page', username=thread.started_by, _external=true) }}</uri>
+      </author>
+    </entry>
+  {%- endfor -%}
+{%- endblock -%}
diff --git a/app/templates/topics/topic.html b/app/templates/topics/topic.html
index b7e2427..43585bb 100644
--- a/app/templates/topics/topic.html
+++ b/app/templates/topics/topic.html
@@ -20,7 +20,7 @@
   <a href="{{url_for('topics.feed', topic_id=topic.id)}}" class="linkbutton rss">Subscribe via RSS</a>
   <form method="GET">
     <select name="sort_by">
-      <option value="activity"{% if sort_by == 'activity' %}selected{% endif %}>Sorted by activity</option>
+      <option value="activity" {% if sort_by == 'activity' %}selected{% endif %}>Sorted by activity</option>
       <option value="thread" {% if sort_by == 'thread' %}selected{% endif %}>Sorted by newest</option>
     </select>
     <input type="submit" value="Sort">