diff --git a/app/models.py b/app/models.py
index 67fa5f8..0e98d06 100644
--- a/app/models.py
+++ b/app/models.py
@@ -102,6 +102,9 @@ class Users(Model):
     def get_badges(self):
         return Badges.findall({'user_id': int(self.id)})
 
+    def is_subscribed(self, thread_id):
+        return Subscriptions.count({'user_id': self.id, 'thread_id': thread_id}) > 0
+
 
 class Topics(Model):
     table = 'topics'
@@ -327,7 +330,8 @@ class Posts(Model):
             for mention in html_content.mentions:
                 Mentions.create({
                     'revision_id': revision.id,
-                    'mentioned_iser_id': mention['mentioned_iser_id'],
+                    'mentioned_user_id': mention['mentioned_user_id'],
+                    'original_mention_text': mention['mention_text'],
                     'start_index': mention['start'],
                     'end_index': mention['end'],
                 })
@@ -335,6 +339,32 @@ class Posts(Model):
             post.update({'current_revision_id': revision.id})
             return post
 
+    def edit(self, new_content: str, language: str = 'babycode'):
+        from .lib.babycode import babycode_to_html, babycode_to_rssxml, BABYCODE_VERSION
+        html_content = babycode_to_html(new_content)
+        rssxml_content = babycode_to_rssxml(new_content)
+        with db.transaction():
+            revision = PostHistory.create({
+                'post_id': self.id,
+                'content': html_content.result,
+                'content_rss': rssxml_content,
+                'is_initial_revision': False,
+                'original_markup': new_content,
+                'markup_language': language,
+                'format_version': BABYCODE_VERSION,
+                })
+
+            for mention in html_content.mentions:
+                Mentions.create({
+                    'revision_id': revision.id,
+                    'mentioned_user_id': mention['mentioned_user_id'],
+                    'original_mention_text': mention['mention_text'],
+                    'start_index': mention['start'],
+                    'end_index': mention['end'],
+                })
+
+            self.update({'current_revision_id': revision.id})
+
 class PostHistory(Model):
     table = 'post_history'
 
diff --git a/app/routes/posts.py b/app/routes/posts.py
index dda0186..208f29f 100644
--- a/app/routes/posts.py
+++ b/app/routes/posts.py
@@ -1,7 +1,9 @@
-from flask import Blueprint, abort
+from flask import Blueprint, abort, render_template, redirect, url_for, request
 from functools import wraps
 from ..auth import login_required, get_active_user
-from ..models import Posts
+from ..models import Posts, Threads
+from ..util import get_post_url
+from ..db import db
 
 bp = Blueprint('posts', __name__, url_prefix='/posts/')
 
@@ -9,10 +11,11 @@ def ownership_required(view_func):
     @wraps(view_func)
     def wrapper(*args, **kwargs):
         post = Posts.find({'id': kwargs.get('post_id', None)})
+        user = get_active_user()
         if not post:
             abort(404)
 
-        if post.user_id != get_active_user().id:
+        if post.user_id != user.id:
             abort(403)
 
         return view_func(*args, **kwargs)
@@ -35,7 +38,46 @@ def ownership_or_mod_required(view_func):
 @login_required
 @ownership_required
 def edit(post_id):
-    return 'stub'
+    post = Posts.find({'id': post_id})
+    thread = Threads.find({'id': post.thread_id})
+    user = get_active_user()
+    if not thread:
+        # what?
+        abort(404)
+
+    if thread.locked() and not user.is_mod():
+        abort(403)
+
+    thread_predicate = f'{Posts.FULL_POSTS_QUERY} WHERE posts.thread_id = ?'
+
+    context_prev_q = f'{thread_predicate} AND posts.created_at < ? ORDER BY posts.created_at DESC LIMIT 2'
+    context_next_q = f'{thread_predicate} AND posts.created_at > ? ORDER BY posts.created_at ASC LIMIT 2'
+
+    context_next = db.query(context_next_q, thread.id, post.created_at)
+    context_prev = db.query(context_prev_q, thread.id, post.created_at)
+
+    return render_template(
+        'posts/edit.html', post=post.get_full_post_view(),
+        context_next=context_next, context_prev=context_prev
+        )
+
+@bp.post('/<int:post_id>/edit/')
+@login_required
+@ownership_required
+def edit_post(post_id):
+    post = Posts.find({'id': post_id})
+    thread = Threads.find({'id': post.thread_id})
+    user = get_active_user()
+    if not thread:
+        # what?
+        abort(404)
+
+    if thread.locked() and not user.is_mod():
+        abort(403)
+
+    post.edit(request.form.get('babycode_content', ''))
+
+    return redirect(get_post_url(post.id, _anchor=True))
 
 @bp.get('/<int:post_id>/delete/')
 @login_required
diff --git a/app/routes/threads.py b/app/routes/threads.py
index b38b3a5..1c9a330 100644
--- a/app/routes/threads.py
+++ b/app/routes/threads.py
@@ -1,7 +1,8 @@
 from flask import Blueprint, redirect, url_for, render_template, request, abort
 from functools import wraps
 from ..auth import login_required, get_active_user
-from ..models import Threads, Posts, Topics, Users, Reactions
+from ..models import Threads, Posts, Topics, Users, Reactions, Subscriptions
+from ..util import get_form_checkbox, time_now
 import math
 
 bp = Blueprint('threads', __name__, url_prefix='/threads/')
@@ -56,7 +57,15 @@ def thread(thread_id, slug):
             page = max(1, min(int(request.args.get('page', default=1)), page_count))
         except ValueError:
             abort(404)
-    return render_template('threads/thread.html', thread=thread, posts=thread.get_posts(PER_PAGE, page), page=page, page_count=page_count, topic=topic, started_by=started_by, topics=Topics.get_list(), Reactions=Reactions)
+    posts = thread.get_posts(PER_PAGE, page)
+    last_post = posts[-1]
+    return render_template(
+        'threads/thread.html', thread=thread,
+        posts=posts, page=page,
+        page_count=page_count, topic=topic,
+        started_by=started_by, topics=Topics.get_list(),
+        Reactions=Reactions, last_post=last_post
+        )
 
 @bp.post('/<int:thread_id>/')
 @login_required
@@ -68,6 +77,13 @@ def reply(thread_id):
     if not user.can_post_to_thread_or_topic(thread):
         return redirect(url_for('.thread_by_id', thread_id=thread_id))
     post = Posts.new(user.id, thread.id, request.form.get('babycode_content'))
+    if get_form_checkbox('subscribe'):
+        if not Subscriptions.find({'user_id': user.id, 'thread_id': thread.id}):
+            Subscriptions.create({
+                'user_id': user.id,
+                'thread_id': thread.id,
+                'last_seen': time_now(),
+                })
     return redirect(url_for('.thread_by_id', thread_id=thread_id, after=post.id, _anchor=f'post-{post.id}'))
 
 @bp.get('/<int:thread_id>/edit/')
@@ -82,6 +98,48 @@ def edit(thread_id):
 def edit_post(thread_id):
     return 'stub'
 
+@bp.post('/<int:thread_id>/subscribe/')
+@login_required
+def subscribe(thread_id):
+    thread = Threads.find({'id': thread_id})
+    if not thread:
+        abort(404)
+
+    user = get_active_user()
+    last_post_id = request.form.get('last_post_id', None)
+    if last_post_id is None:
+        abort(400)
+
+    if user.is_subscribed(thread_id):
+        return redirect(url_for('.thread_by_id', thread_id=thread_id, after=last_post_id))
+
+    Subscriptions.create({
+        'user_id': user.id,
+        'thread_id': thread_id,
+        'last_seen': request.form.get('last_post_timestamp', time_now())
+        })
+
+    return redirect(url_for('.thread_by_id', thread_id=thread_id, after=last_post_id))
+
+@bp.post('/<int:thread_id>/unsubscribe/')
+@login_required
+def unsubscribe(thread_id):
+    thread = Threads.find({'id': thread_id})
+    if not thread:
+        abort(404)
+
+    user = get_active_user()
+    last_post_id = request.form.get('last_post_id', None)
+    if last_post_id is None:
+        abort(400)
+
+    subscription = Subscriptions.find({'user_id': user.id, 'thread_id': thread_id})
+    if not subscription:
+        return redirect(url_for('.thread_by_id', thread_id=thread_id, after=last_post_id))
+
+    subscription.delete()
+    return redirect(url_for('.thread_by_id', thread_id=thread_id, after=last_post_id))
+
 @bp.get('/<int:thread_id>/feed.atom/')
 def feed(thread_id):
     return 'stub'
diff --git a/app/templates/common/macros.html b/app/templates/common/macros.html
index 5415d8e..217b181 100644
--- a/app/templates/common/macros.html
+++ b/app/templates/common/macros.html
@@ -1,7 +1,8 @@
 {%- from 'common/icons.html' import icn_info, icn_warn, icn_error, icn_bookmark -%}
 
 {% macro timestamp(unix_ts) -%}
-<span class="timestamp" data-utc="{{ unix_ts }}">{{ unix_ts | ts_datetime('%Y-%m-%d %H:%M')}} <abbr title="Server Time">ST</abbr></span>
+{#<span class="timestamp" data-utc="{{ unix_ts }}">{{ unix_ts | ts_datetime('%Y-%m-%d %H:%M')}} <abbr title="Server Time">ST</abbr></span>#}
+<time datetime="{{ unix_ts | iso8601 }}">{{ unix_ts | ts_datetime('%Y-%m-%d %H:%M')}} <abbr title="Server Time">ST</abbr></time>
 {%- endmacro %}
 
 {% macro subheader(title, desc='') -%}
@@ -103,9 +104,9 @@
     <button type="button" class="minimal">&bullet;</button>
     <button type="button" class="minimal"><img src="/static/emoji/angry.png" class="emoji"></button>
   </span>
-  <a href="##">babycode help</a>
 </span>
 <textarea name="babycode_content" id="{{id}}" class="babycode-editor" placeholder="{{placeholder}}" {{'required' if required else ''}}>{{ prefill }}</textarea>
+<a href="##">babycode help</a>
 {%- endif -%}
 {%- endcall -%}
 {%- endmacro %}
@@ -142,11 +143,17 @@
 </div>
 <div class="post-content">
   <div class="plank even minimal secondary-bg no-shadow post-info">
-    <a href="{{get_post_url(post.id, _anchor=true)}}"><i>Posted on {{timestamp(post.created_at)}}</i></a>
+    <a href="{{get_post_url(post.id, _anchor=true)}}">
+      {%- if post.edited_at <= post.created_at -%}
+      <i>Posted on {{timestamp(post.created_at)}}</i>
+      {%- else -%}
+      <i>Edited on {{timestamp(post.edited_at)}}</i>
+      {%- endif -%}
+    </a>
     {%- if show_toolbar -%}
     <span class="thread-actions">
       {%- if owns -%}
-      <a class="linkbutton" href="{{url_for('posts.edit', post_id=post.id)}}">Edit</a>
+      <a class="linkbutton" href="{{url_for('posts.edit', post_id=post.id, _anchor='babycode-content')}}">Edit</a>
       {%- endif -%}
       {%- if can_reply -%}
       <button disabled title="This feature requires JavaScript to be enabled.">Quote</button>
@@ -158,28 +165,37 @@
     </span>
     {%- endif -%}
   </div>
-  <div class="plank even no-shadow post-content-inner minimal">{{post.content | safe}}
-    {%- if render_sig and post.signature_rendered -%}
-    <aside class="post-signature">{{post.signature_rendered | safe}}</aside>
+  <div class="plank even no-shadow post-content-inner minimal">
+    {%- if not is_editing -%}
+      {{post.content | safe}}
+      {%- if render_sig and post.signature_rendered -%}
+      <aside class="post-signature">{{post.signature_rendered | safe}}</aside>
+      {%- endif -%}
+    {%- else -%}
+      {{- babycode_editor_component(prefill=post.original_markup) -}}
     {%- endif -%}
   </div>
-  {%- if show_reactions -%}
   <div class="plank even secondary-bg minimal no-shadow">
-    <span class="button-row">
-      {%- for reaction in Reactions.for_post(post.id) -%}
-      {% set reactors = Reactions.get_users(post.id, reaction.reaction_text) | map(attribute='username') | list %}
-      {% set reactors_trimmed = reactors[:10] %}
-      {% set reactors_str = reactors_trimmed | join (',\n') %}
-      {% if reactors | count > 10 %}
-        {% set reactors_str = reactors_str + '\n...and many others' %}
-      {% endif %}
-      {% set has_reacted = get_active_user() is not none and get_active_user().username in reactors %}
-      <button disabled title="{{reactors_str}}" class="minimal {{'alt' if has_reacted else ''}}"><img src="/static/emoji/{{reaction.reaction_text}}.png">{{reaction.c}}</button>
-      {%- endfor -%}
-    </span>
-    {%- if is_logged_in() -%}<button disabled title="This feature requires JavaScript to be enabled.">Add reaction</button>{%- endif -%}
+    {%- if show_reactions -%}
+      <span class="button-row">
+        {%- for reaction in Reactions.for_post(post.id) -%}
+        {% set reactors = Reactions.get_users(post.id, reaction.reaction_text) | map(attribute='username') | list %}
+        {% set reactors_trimmed = reactors[:10] %}
+        {% set reactors_str = reactors_trimmed | join (',\n') %}
+        {% if reactors | count > 10 %}
+          {% set reactors_str = reactors_str + '\n...and many others' %}
+        {% endif %}
+        {% set has_reacted = get_active_user() is not none and get_active_user().username in reactors %}
+        <button disabled title="{{reactors_str}}" class="minimal {{'alt' if has_reacted else ''}}"><img src="/static/emoji/{{reaction.reaction_text}}.png">{{reaction.c}}</button>
+        {%- endfor -%}
+      </span>
+      {%- if is_logged_in() -%}<button disabled title="This feature requires JavaScript to be enabled.">Add reaction</button>{%- endif -%}
+    {%- elif is_editing -%}
+      <input type="submit" value="Save">
+      <a href="{{get_post_url(post.id, _anchor=true)}}" class="linkbutton warn">Cancel</a>
+    {%- endif -%}
   </div>
-  {%- endif -%}
+
 </div>
 {%- endmacro %}
 
diff --git a/app/templates/posts/edit.html b/app/templates/posts/edit.html
new file mode 100644
index 0000000..e9f9ab3
--- /dev/null
+++ b/app/templates/posts/edit.html
@@ -0,0 +1,24 @@
+{%- from 'common/macros.html' import full_post with context -%}
+{%- extends 'base.html' -%}
+{%- block title -%}editing a post{%- endblock -%}
+{%- block content -%}
+  {%- for post in context_prev -%}
+  <div class="post plank">{{- full_post(post=post, show_toolbar=false, show_reactions=false) -}}</div>
+  {%- endfor -%}
+  <div class="plank secondary-bg context-explain">
+    <span>&uarr;&uarr;&uarr;</span>
+    <i>Context</i>
+    <span>&uarr;&uarr;&uarr;</span>
+  </div>
+  <form class="post plank" method="POST">
+  {{- full_post(post=post, is_editing=true, show_toolbar=false, show_reactions=false) -}}
+  </form>
+  <div class="plank secondary-bg context-explain">
+    <span>&darr;&darr;&darr;</span>
+    <i>Context</i>
+    <span>&darr;&darr;&darr;</span>
+  </div>
+  {%- for post in context_next -%}
+  <div class="post plank">{{- full_post(post=post, show_toolbar=false, show_reactions=false) -}}</div>
+  {%- endfor -%}
+{%- endblock -%}
diff --git a/app/templates/threads/thread.html b/app/templates/threads/thread.html
index 9a5b53a..0086528 100644
--- a/app/templates/threads/thread.html
+++ b/app/templates/threads/thread.html
@@ -24,7 +24,11 @@
   {%- if thread.user_id == get_active_user().id -%}
   <a class="linkbutton" href="{{url_for('threads.edit', thread_id=thread.id)}}">Edit</a>
   {%- endif -%}
-  <button>Subscribe</button>
+  <form action="{{url_for('threads.subscribe' if not get_active_user().is_subscribed(thread.id) else 'threads.unsubscribe', thread_id=thread.id)}}" method="POST">
+    <input type="hidden" name="last_post_timestamp" value="{{last_post.created_at}}">
+    <input type="hidden" name="last_post_id" value="{{last_post.id}}">
+    <input type="submit" value="{{'Subscribe' if not get_active_user().is_subscribed(thread.id) else 'Unsubscribe'}}">
+  </form>
   <button disabled title="This feature requires JavaScript to be enabled.">{{icn_bookmark(24)}}Bookmark&hellip;</button>
   {%- endif -%}
   <a href="{{url_for('threads.feed', thread_id=thread.id)}}" class="linkbutton rss">Subscribe via RSS</a>
diff --git a/app/util.py b/app/util.py
index a9fbf2d..6b1b9f7 100644
--- a/app/util.py
+++ b/app/util.py
@@ -1,6 +1,7 @@
-from flask import url_for, session
+from flask import url_for, session, request
 from .models import Posts, Threads
 from .auth import is_logged_in
+import time
 
 def get_post_url(post_id, _anchor=False, external=False):
     post = Posts.find({'id': post_id})
@@ -24,3 +25,9 @@ def get_csrf_token():
 
 def csrf_input():
     return f'<input type="hidden" name="csrf" value="{get_csrf_token()}">'
+
+def get_form_checkbox(name: str) -> bool:
+    return request.form.get(name, None) == 'on'
+
+def time_now() -> int:
+    return int(time.time())
diff --git a/data/static/css/style.css b/data/static/css/style.css
index c4cf7d4..e3f7404 100644
--- a/data/static/css/style.css
+++ b/data/static/css/style.css
@@ -182,7 +182,7 @@ button, .linkbutton, input[type="submit"] {
 }
 
 .tab-content {
-
+  min-height: 250px;
 
   &.hidden {
     display: none;
@@ -192,7 +192,7 @@ button, .linkbutton, input[type="submit"] {
 
 .babycode-editor {
   width: 100%;
-  height: 150px;
+  min-height: 150px;
 }
 
 .post-edit-form {
@@ -620,6 +620,11 @@ form.full-width {
   }
 }
 
+.context-explain {
+  display: flex;
+  justify-content: space-evenly;
+}
+
 /* babycode tags */
 .inline-code {
   background-color: var(--code-bg-color);