diff --git a/Makefile b/Makefile
index 080be0268b0..6bdc65fa1a4 100644
--- a/Makefile
+++ b/Makefile
@@ -65,15 +65,11 @@ pep_rss:
 	$(PYTHON) generate_rss.py
 
 pages: pep_rss
-	$(SPHINX_BUILD) --index-file
+	$(SPHINX_BUILD) --build-dirs
 
 sphinx:
 	$(SPHINX_BUILD)
 
-# for building Sphinx without a web-server
-sphinx-local:
-	$(SPHINX_BUILD) --build-files
-
 fail-warning:
 	$(SPHINX_BUILD) --fail-on-warning
 
diff --git a/build.py b/build.py
old mode 100644
new mode 100755
index 784fbea547d..decb84e71eb
--- a/build.py
+++ b/build.py
@@ -1,3 +1,7 @@
+#!/usr/bin/env python3
+# This file is placed in the public domain or under the
+# CC0-1.0-Universal license, whichever is more permissive.
+
 """Build script for Sphinx documentation"""
 
 import argparse
@@ -9,17 +13,29 @@
 def create_parser():
     parser = argparse.ArgumentParser(description="Build PEP documents")
     # alternative builders:
-    parser.add_argument("-l", "--check-links", action="store_true")
-    parser.add_argument("-f", "--build-files", action="store_true")
-    parser.add_argument("-d", "--build-dirs", action="store_true")
+    builders = parser.add_mutually_exclusive_group()
+    builders.add_argument("-l", "--check-links", action="store_const",
+                          dest="builder", const="linkcheck",
+                          help='Check validity of links within PEP sources. '
+                               'Cannot be used with "-f" or "-d".')
+    builders.add_argument("-f", "--build-files", action="store_const",
+                          dest="builder", const="html",
+                          help='Render PEPs to "pep-NNNN.html" files (default). '
+                               'Cannot be used with "-d" or "-l".')
+    builders.add_argument("-d", "--build-dirs", action="store_const",
+                          dest="builder", const="dirhtml",
+                          help='Render PEPs to "index.html" files within "pep-NNNN" directories. '
+                               'Cannot be used with "-f" or "-l".')
 
     # flags / options
-    parser.add_argument("-w", "--fail-on-warning", action="store_true")
-    parser.add_argument("-n", "--nitpicky", action="store_true")
-    parser.add_argument("-j", "--jobs", type=int, default=1)
-
-    # extra build steps
-    parser.add_argument("-i", "--index-file", action="store_true")  # for PEP 0
+    parser.add_argument("-w", "--fail-on-warning", action="store_true",
+                        help="Fail the Sphinx build on any warning.")
+    parser.add_argument("-n", "--nitpicky", action="store_true",
+                        help="Run Sphinx in 'nitpicky' mode, "
+                             "warning on every missing reference target.")
+    parser.add_argument("-j", "--jobs", type=int, default=1,
+                        help="How many parallel jobs to run (if supported). "
+                             "Integer, default 1.")
 
     return parser.parse_args()
 
@@ -45,15 +61,11 @@ def create_index_file(html_root: Path, builder: str) -> None:
     doctree_directory = build_directory / ".doctrees"
 
     # builder configuration
-    if args.build_files:
-        sphinx_builder = "html"
-    elif args.build_dirs:
-        sphinx_builder = "dirhtml"
-    elif args.check_links:
-        sphinx_builder = "linkcheck"
+    if args.builder is not None:
+        sphinx_builder = args.builder
     else:
         # default builder
-        sphinx_builder = "dirhtml"
+        sphinx_builder = "html"
 
     # other configuration
     config_overrides = {}
@@ -71,6 +83,5 @@ def create_index_file(html_root: Path, builder: str) -> None:
         parallel=args.jobs,
     )
     app.build()
-    
-    if args.index_file:
-        create_index_file(build_directory, sphinx_builder)
+
+    create_index_file(build_directory, sphinx_builder)
diff --git a/conf.py b/conf.py
index b7b37405520..a508a96f533 100644
--- a/conf.py
+++ b/conf.py
@@ -1,3 +1,6 @@
+# This file is placed in the public domain or under the
+# CC0-1.0-Universal license, whichever is more permissive.
+
 """Configuration for building PEPs using Sphinx."""
 
 from pathlib import Path
@@ -43,7 +46,6 @@
 
 # HTML output settings
 html_math_renderer = "maths_to_html"  # Maths rendering
-html_title = "peps.python.org"  # Set <title/>
 
 # Theme settings
 html_theme_path = ["pep_sphinx_extensions"]
diff --git a/contents.rst b/contents.rst
index 658655e4044..94295408341 100644
--- a/contents.rst
+++ b/contents.rst
@@ -1,9 +1,11 @@
+.. This file is placed in the public domain or under the
+   CC0-1.0-Universal license, whichever is more permissive.
 
 Python Enhancement Proposals (PEPs)
 ***********************************
 
 
-This is an internal Sphinx page, please go to the :doc:`PEP Index<pep-0000>`.
+This is an internal Sphinx page, please go to the :doc:`PEP Index <pep-0000>`.
 
 
 .. toctree::
diff --git a/docs/build.rst b/docs/build.rst
new file mode 100644
index 00000000000..0d7aa144dcd
--- /dev/null
+++ b/docs/build.rst
@@ -0,0 +1,106 @@
+..
+   Author: Adam Turner
+
+
+Building PEPs Locally
+=====================
+
+Whilst editing a PEP, it is useful to review the rendered output locally.
+This can also be used to check that the PEP is valid reStructuredText before
+submission to the PEP editors.
+
+The rest of this document assumes you are working from a local clone of the
+`PEPs repository <https://github.com/python/peps>`__, with Python 3.9 or later
+installed.
+
+
+Render PEPs locally
+-------------------
+
+1. Create a virtual environment and install requirements.
+
+   The rest of these instructions assume an active virtual environment named
+   ``venv``.
+   The Python Packaging User Guide contains
+   `instructions on creating a virtual environment <https://packaging.python.org/en/latest/guides/installing-using-pip-and-virtual-environments/#creating-a-virtual-environment>`__
+   for reference.
+
+   .. code-block:: console
+
+      (venv) $ python -m pip install --upgrade pip
+      (venv) $ python -m pip install -r requirements.txt
+
+2. **(Optional)** Delete prior build files.
+   Generally only needed when making changes to the rendering system itself.
+
+   .. code-block:: console
+
+      $ rm -rf build
+
+3. Run the build script:
+
+   .. code-block:: console
+
+      (venv) $ make sphinx
+
+   If you don't have access to ``make``, run:
+
+   .. code-block:: ps1con
+
+      (venv) PS> python build.py
+
+   .. note::
+
+      There may be a series of warnings about unreferenced citations or labels.
+      Whilst these are valid warnings, they do not impact the build process.
+
+4. Navigate to the ``build`` directory of your PEPs repo to find the HTML pages.
+   PEP 0 provides a formatted index, and may be a useful reference.
+
+
+``build.py`` tools
+------------------
+
+Several additional tools can be run through ``build.py``, or the Makefile.
+
+
+Check links
+'''''''''''
+
+Check the validity of links within PEP sources (runs the `Sphinx linkchecker
+<https://www.sphinx-doc.org/en/master/usage/builders/index.html#sphinx.builders.linkcheck.CheckExternalLinksBuilder>`__).
+
+.. code-block:: console
+
+    (venv) $ python build.py --check-links
+    (venv) $ make check-links
+
+
+Stricter rendering
+''''''''''''''''''
+
+Run in `nit-picky <https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-nitpicky>`__
+mode.
+This generates warnings for all missing references.
+
+.. code-block:: console
+
+    (venv) $ python build.py --nitpicky
+
+Fail the build on any warning.
+As of January 2022, there are around 250 warnings when building the PEPs.
+
+.. code-block:: console
+
+    (venv) $ python build.py --fail-on-warning
+    (venv) $ make fail-warning
+
+
+``build.py`` usage
+------------------
+
+For details on the command-line options to the ``build.py`` script, run:
+
+.. code-block:: console
+
+    (venv) $ python build.py --help
diff --git a/docs/rendering_system.rst b/docs/rendering_system.rst
new file mode 100644
index 00000000000..bf793d5142e
--- /dev/null
+++ b/docs/rendering_system.rst
@@ -0,0 +1,242 @@
+..
+   Author: Adam Turner
+
+   We can't use :pep:`N` references in this document, as they use links relative
+   to the current file, which doesn't work in a subdirectory like this one.
+
+
+An Overview of the PEP Rendering System
+=======================================
+
+This document provides an overview of the PEP rendering system, as a companion
+to :doc:`PEP 676 <../pep-0676>`.
+
+
+1. Configuration
+----------------
+
+Configuration is stored in three files:
+
+- ``conf.py`` contains the majority of the Sphinx configuration
+- ``contents.rst`` creates the Sphinx-mandated table of contents directive
+- ``pep_sphinx_extensions/pep_theme/theme.conf`` sets the Pygments themes
+
+The configuration:
+
+- registers the custom Sphinx extension
+- sets both ``.txt`` and ``.rst`` suffixes to be parsed as PEPs
+- tells Sphinx which source files to use
+- registers the PEP theme, maths renderer, and template
+- disables some default settings that are covered in the extension
+- sets the default and "dark mode" code formatter styles
+
+
+2. Orchestration
+----------------
+
+``build.py`` manages the rendering process.
+Usage is covered in :doc:`build`.
+
+
+3. Extension
+------------
+
+The Sphinx extension and theme are contained in the ``pep_sphinx_extensions``
+directory.
+The following is a brief overview of the stages of the PEP rendering process,
+and how the extension functions at each point.
+
+
+3.1 Extension setup
+'''''''''''''''''''
+
+The extension registers several objects:
+
+- ``FileBuilder`` and ``DirectoryBuilder`` run the build process for file- and
+  directory-based building, respectively.
+- ``PEPParser`` registers the custom document transforms and parses PEPs to
+  a Docutils document.
+- ``PEPTranslator`` converts a Docutils document into HTML.
+- ``PEPRole`` handles ``:pep:`` roles in the reStructuredText source.
+
+The extension also patches default behaviour:
+
+- updating the default settings
+- updating the Docutils inliner
+- using HTML maths display over MathJax
+
+
+3.2 Builder initialised
+'''''''''''''''''''''''
+
+After the Sphinx builder object is created and initialised, we ensure the
+configuration is correct for the builder chosen.
+
+Currently this involves updating the relative link template.
+See ``_update_config_for_builder`` in ``pep_sphinx_extensions/__init__.py``.
+
+
+3.3 Before documents are read
+'''''''''''''''''''''''''''''
+
+The ``create_pep_zero`` hook is called. See `5. PEP 0`_.
+
+
+3.4 Read document
+'''''''''''''''''
+
+Parsing the document is handled by ``PEPParser``
+(``pep_sphinx_extensions.pep_processor.parsing.pep_parser.PEPParser``), a
+lightweight wrapper over ``sphinx.parsers.RSTParser``.
+
+``PEPParser`` reads the document with leading :rfc:`2822` headers and registers
+the transforms we want to apply.
+These are:
+
+- ``PEPHeaders``
+- ``PEPTitle``
+- ``PEPContents``
+- ``PEPFooter``
+
+Transforms are then applied in priority order.
+
+
+3.4.1 ``PEPRole`` role
+**********************
+
+This overrides the built-in ``:pep:`` role to return the correct URL.
+
+
+3.4.2 ``PEPHeaders`` transform
+******************************
+
+PEPs start with a set of :rfc:`2822` headers, per :doc:`PEP 1 <../pep-0001>`.
+This transform validates that the required headers are present and of the
+correct data type, and removes headers not for display.
+It must run before the ``PEPTitle`` transform.
+
+
+3.4.3 ``PEPTitle`` transform
+****************************
+
+We generate the title node from the parsed title in the PEP headers, and make
+all nodes in the document children of the new title node.
+This transform must also handle parsing reStructuredText markup within PEP
+titles, such as :doc:`PEP 604 <../pep-0604>`.
+
+
+3.4.4 ``PEPContents`` transform
+*******************************
+
+The automatic table of contents (TOC) is inserted in this transform in a
+two-part process.
+
+First, the transform inserts a placeholder for the TOC and a horizontal rule
+after the document title and PEP headers.
+A callback transform then recursively walks the document to create the TOC,
+starting from after the placeholder node.
+Whilst walking the document, all reference nodes in the titles are removed, and
+titles are given a self-link.
+
+
+3.4.5 ``PEPFooter`` transform
+*****************************
+
+This first builds a map of file modification times from a single git call, as
+a speed-up. This will return incorrect results on a shallow checkout of the
+repository, as is the default on continuous integration systems.
+
+We then attempt to remove any empty references sections, and append metadata in
+the footer (source link and last modified timestamp).
+
+
+3.5 Prepare for writing
+''''''''''''''''''''''''
+
+``pep_html_builder.FileBuilder.prepare_writing`` initialises the bare miniumum
+of the Docutils writer and the settings for writing documents.
+This provides a significant speed-up over the base Sphinx implementation, as
+most of the data automatically initialised was unused.
+
+
+3.6 Translate Docutils to HTML
+'''''''''''''''''''''''''''''''
+
+``PEPTranslator`` overrides paragraph and reference logic to replicate
+processing from the previous ``docutils.writers.pep``-based system.
+Paragraphs are made compact where possible by omitting ``<p>`` tags, and
+footnote references are be enclosed in square brackets.
+
+
+3.7 Prepare for export to Jinja
+'''''''''''''''''''''''''''''''
+
+Finally in ``pep_html_builder``, we gather all the parts to be passed to the
+Jinja template.
+This is also where we create the sidebar table of contents.
+
+The HTML files are then written out to the build directory.
+
+
+4. Theme
+--------
+
+The theme is comprised of the HTML template in
+``pep_sphinx_extensions/pep_theme/templates/page.html`` and the stylesheets in
+``pep_sphinx_extensions/pep_theme/static``.
+
+The template is entirely self-contained, not relying on any default behaviour
+from Sphinx.
+It specifies the CSS files to include, the favicon, and basic semantic
+information for the document structure.
+
+The styles are defined in two parts:
+
+- ``style.css`` handles the meat of the layout
+- ``mq.css`` adds media queries for a responsive design
+
+
+5. \PEP 0
+---------
+
+The generation of the index, PEP 0, happens in three phases.
+The reStructuredText source file is generated, it is then added to Sphinx, and
+finally the data is post processed.
+
+
+5.1 File creation
+'''''''''''''''''
+
+``pep-0000.rst`` is created during a callback, before documents are loaded by
+Sphinx.
+
+We first parse the individual PEP files to get the :rfc:`2822` header, and then
+parse and validate that metadata.
+
+After collecting and validating all the PEP data, the index itself is created in
+three steps:
+
+    1. Output the header text
+    2. Output the category and numerical indices
+    3. Output the author index
+
+The ``AUTHOR_OVERRIDES.csv`` file can be used to override an author's name in
+the PEP 0 output.
+
+We then add the newly created PEP 0 file to two Sphinx variables so that it will
+be processed as a normal source document.
+
+
+5.2 Post processing
+'''''''''''''''''''
+
+The ``PEPHeaders`` transform schedules the \PEP 0 post-processing code.
+This serves two functions: masking email addresses and linking numeric
+PEP references to the actual documents.
+
+
+6. RSS Feed
+-----------
+
+The RSS feed is created by extracting the header metadata and abstract from the
+ten most recent PEPs.
diff --git a/generate_rss.py b/generate_rss.py
old mode 100644
new mode 100755
index 88798cb798a..efeeb3c4d6b
--- a/generate_rss.py
+++ b/generate_rss.py
@@ -1,3 +1,7 @@
+#!/usr/bin/env python3
+# This file is placed in the public domain or under the
+# CC0-1.0-Universal license, whichever is more permissive.
+
 import datetime
 import email.utils
 from pathlib import Path
diff --git a/pep-0009.txt b/pep-0009.txt
index a94b4f5917f..4a9f3d6681c 100644
--- a/pep-0009.txt
+++ b/pep-0009.txt
@@ -11,6 +11,7 @@ Post-History:
 Resolution: https://mail.python.org/mailman/private/peps/2016-January/001165.html
 
 ::
+
   Update
 
       As of 05-Jan-2016, this PEP is officially deprecated and replaced
@@ -226,10 +227,11 @@ Resolution: https://mail.python.org/mailman/private/peps/2016-January/001165.htm
 
 
 
-Local Variables:
-mode: indented-text
-indent-tabs-mode: nil
-sentence-end-double-space: t
-fill-column: 70
-coding: utf-8
-End:
+..
+   Local Variables:
+   mode: indented-text
+   indent-tabs-mode: nil
+   sentence-end-double-space: t
+   fill-column: 70
+   coding: utf-8
+   End:
diff --git a/pep-0011.txt b/pep-0011.txt
index dba6ec7b364..b867018c80c 100644
--- a/pep-0011.txt
+++ b/pep-0011.txt
@@ -287,7 +287,8 @@ Copyright
 This document has been placed in the public domain.
 
 
-..
+
+..
    Local Variables:
    mode: indented-text
    indent-tabs-mode: nil
diff --git a/pep-0610.rst b/pep-0610.rst
index f41e4616c65..d4aacffa44d 100644
--- a/pep-0610.rst
+++ b/pep-0610.rst
@@ -568,7 +568,8 @@ This document is placed in the public domain or under the
 CC0-1.0-Universal license, whichever is more permissive.
 
 
-..
+
+..
    Local Variables:
    mode: indented-text
    indent-tabs-mode: nil
diff --git a/pep-0625.rst b/pep-0625.rst
index 4b39fba1d7f..dcebad94e63 100644
--- a/pep-0625.rst
+++ b/pep-0625.rst
@@ -158,7 +158,8 @@ This document is placed in the public domain or under the CC0-1.0-Universal
 license, whichever is more permissive.
 
 
-..
+
+..
     Local Variables:
     mode: indented-text
     indent-tabs-mode: nil
diff --git a/pep-0676.rst b/pep-0676.rst
index b86dbc9a42c..b955e1f920a 100644
--- a/pep-0676.rst
+++ b/pep-0676.rst
@@ -106,6 +106,9 @@ The proposed specification for rendering the PEP files to HTML is as per the
 The rendered PEPs MUST be available at `peps.python.org`_. These SHOULD be
 hosted as static files, and MAY be behind a content delivery network (CDN).
 
+A service to render previews of pull requests SHOULD be provided. This service
+MAY be integrated with the hosting and deployment solution.
+
 The following redirect rules MUST be created for the `python.org`_ domain:
 
 * ``/peps/``            -> https://peps.python.org/
diff --git a/pep-3139.txt b/pep-3139.txt
index b2a19e006ab..d6b79fffff9 100644
--- a/pep-3139.txt
+++ b/pep-3139.txt
@@ -185,10 +185,11 @@ Copyright
 
 
 
-Local Variables:
-mode: indented-text
-indent-tabs-mode: nil
-sentence-end-double-space: t
-fill-column: 70
-coding: utf-8
-End:
+..
+   Local Variables:
+   mode: indented-text
+   indent-tabs-mode: nil
+   sentence-end-double-space: t
+   fill-column: 70
+   coding: utf-8
+   End:
diff --git a/pep_sphinx_extensions/LICENCE.rst b/pep_sphinx_extensions/LICENCE.rst
new file mode 100644
index 00000000000..f147a8023e3
--- /dev/null
+++ b/pep_sphinx_extensions/LICENCE.rst
@@ -0,0 +1,2 @@
+This files in this directory are placed in the public domain or under the
+CC0-1.0-Universal license, whichever is more permissive.
\ No newline at end of file
diff --git a/pep_sphinx_extensions/__init__.py b/pep_sphinx_extensions/__init__.py
index f302b14b7b9..5479a1dc132 100644
--- a/pep_sphinx_extensions/__init__.py
+++ b/pep_sphinx_extensions/__init__.py
@@ -39,7 +39,7 @@ def _depart_maths():
 
 def _update_config_for_builder(app: Sphinx):
     if app.builder.name == "dirhtml":
-        environment.default_settings["pep_url"] = "../pep-{:0>4}"
+        app.env.settings["pep_url"] = "../pep-{:0>4}"
 
 
 def setup(app: Sphinx) -> dict[str, bool]:
@@ -50,12 +50,17 @@ def setup(app: Sphinx) -> dict[str, bool]:
     # Register plugin logic
     app.add_builder(pep_html_builder.FileBuilder, override=True)
     app.add_builder(pep_html_builder.DirectoryBuilder, override=True)
+
     app.add_source_parser(pep_parser.PEPParser)  # Add PEP transforms
-    app.add_role("pep", pep_role.PEPRole(), override=True)  # Transform PEP references to links
+
     app.set_translator("html", pep_html_translator.PEPTranslator)  # Docutils Node Visitor overrides (html builder)
     app.set_translator("dirhtml", pep_html_translator.PEPTranslator)  # Docutils Node Visitor overrides (dirhtml builder)
-    app.connect("env-before-read-docs", create_pep_zero)  # PEP 0 hook
+
+    app.add_role("pep", pep_role.PEPRole(), override=True)  # Transform PEP references to links
+
+    # Register event callbacks
     app.connect("builder-inited", _update_config_for_builder)  # Update configuration values for builder used
+    app.connect("env-before-read-docs", create_pep_zero)  # PEP 0 hook
 
     # Mathematics rendering
     inline_maths = HTMLTranslator.visit_math, _depart_maths
diff --git a/pep_sphinx_extensions/pep_processor/html/pep_html_builder.py b/pep_sphinx_extensions/pep_processor/html/pep_html_builder.py
index 703aa3af36e..5af7a49b86c 100644
--- a/pep_sphinx_extensions/pep_processor/html/pep_html_builder.py
+++ b/pep_sphinx_extensions/pep_processor/html/pep_html_builder.py
@@ -16,12 +16,12 @@ class FileBuilder(StandaloneHTMLBuilder):
     indexer = None
     relations = {}
     _script_files = _css_files = []
+    globalcontext = {"script_files": [], "css_files": []}
 
     def prepare_writing(self, _doc_names: set[str]) -> None:
         self.docwriter = HTMLWriter(self)
         _opt_parser = OptionParser([self.docwriter], defaults=self.env.settings, read_config_files=True)
         self.docsettings = _opt_parser.get_default_values()
-        self.globalcontext = {"docstitle": self.config.html_title, "script_files": [], "css_files": []}
 
     def get_doc_context(self, docname: str, body: str, _metatags: str) -> dict:
         """Collect items for the template context of a page."""
@@ -36,9 +36,13 @@ def get_doc_context(self, docname: str, body: str, _metatags: str) -> dict:
 
         # local table of contents
         toc_tree = self.env.tocs[docname].deepcopy()
-        for node in toc_tree.traverse(nodes.reference):
-            node["refuri"] = node["anchorname"] or '#'  # fix targets
-        toc = self.render_partial(toc_tree)["fragment"]
+        if len(toc_tree[0]) > 1:
+            toc_tree = toc_tree[0][1]  # don't include document title
+            for node in toc_tree.traverse(nodes.reference):
+                node["refuri"] = node["anchorname"] or '#'  # fix targets
+            toc = self.render_partial(toc_tree)["fragment"]
+        else:
+            toc = ""  # PEPs with no sections -- 9, 210
 
         return {"title": title, "sourcename": source_name, "toc": toc, "body": body}
 
diff --git a/pep_sphinx_extensions/pep_processor/transforms/pep_footer.py b/pep_sphinx_extensions/pep_processor/transforms/pep_footer.py
index 1f907dfb701..7f8c0f01535 100644
--- a/pep_sphinx_extensions/pep_processor/transforms/pep_footer.py
+++ b/pep_sphinx_extensions/pep_processor/transforms/pep_footer.py
@@ -18,8 +18,8 @@ class PEPFooter(transforms.Transform):
 
     """
 
-    # Set low priority so ref targets aren't removed before they are needed
-    default_priority = 999
+    # Uses same priority as docutils.transforms.TargetNotes
+    default_priority = 520
 
     def apply(self) -> None:
         pep_source_path = Path(self.document["source"])
@@ -34,13 +34,21 @@ def apply(self) -> None:
             if "references" in title_words:
                 # Remove references section if there are no displayed
                 # footnotes (it only has title & link target nodes)
-                if all(isinstance(ref_node, (nodes.title, nodes.target))
-                       for ref_node in section):
+                to_hoist = []
+                types = set()
+                for node in section:
+                    types.add(type(node))
+                    if isinstance(node, nodes.target):
+                        to_hoist.append(node)
+                if types <= {nodes.title, nodes.target}:
+                    section.parent.extend(to_hoist)
                     section.parent.remove(section)
                 break
 
         # Add link to source text and last modified date
         if pep_source_path.stem != "pep-0000":
+            if pep_source_path.stem != "pep-0210":  # 210 is entirely empty, skip
+                self.document += nodes.transition()
             self.document += _add_source_link(pep_source_path)
             self.document += _add_commit_history_info(pep_source_path)
 
diff --git a/pep_sphinx_extensions/pep_theme/static/colour_scheme.js b/pep_sphinx_extensions/pep_theme/static/colour_scheme.js
new file mode 100644
index 00000000000..2cb6e9fabda
--- /dev/null
+++ b/pep_sphinx_extensions/pep_theme/static/colour_scheme.js
@@ -0,0 +1,33 @@
+const dark = document.getElementById("css-dark");
+const pygmentsNormal = document.getElementById("pyg");
+const pygmentsDark = document.getElementById("pyg-dark");
+
+const makeLight = () => {
+    dark.media = pygmentsNormal.media = pygmentsDark.media = ""
+    dark.disabled = pygmentsDark.disabled = true
+    pygmentsNormal.disabled = false
+
+}
+
+const makeDark = () => {
+    dark.media = pygmentsNormal.media = pygmentsDark.media = ""
+    dark.disabled = pygmentsDark.disabled = false
+    pygmentsNormal.disabled = true
+}
+
+
+const toggleColourScheme = () => {
+    if (localStorage.getItem("colour_scheme") === "dark") {
+        makeLight()
+        localStorage.setItem("colour_scheme", "light")
+    } else {
+        makeDark()
+        localStorage.setItem("colour_scheme", "dark")
+    }
+}
+
+/* set colour scheme from local storage */
+document.addEventListener("DOMContentLoaded", () => {
+    if (localStorage.getItem("colour_scheme") === "light") makeLight()
+    if (localStorage.getItem("colour_scheme") === "dark") makeDark()
+})
diff --git a/pep_sphinx_extensions/pep_theme/static/colour_scheme.svg b/pep_sphinx_extensions/pep_theme/static/colour_scheme.svg
new file mode 100644
index 00000000000..78fef233c12
--- /dev/null
+++ b/pep_sphinx_extensions/pep_theme/static/colour_scheme.svg
@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" stroke-width="2" stroke="#777" fill="none" stroke-linecap="round" stroke-linejoin="round">
+<circle cx="12" cy="12" r="9"/>
+<path d="M12 3v18m0-12l4.65-4.65M12 14.3l7.37-7.37M12 19.6l8.85-8.85"/>
+</svg>
diff --git a/pep_sphinx_extensions/pep_theme/static/dark.css b/pep_sphinx_extensions/pep_theme/static/dark.css
new file mode 100644
index 00000000000..314192d94c9
--- /dev/null
+++ b/pep_sphinx_extensions/pep_theme/static/dark.css
@@ -0,0 +1,18 @@
+@charset "UTF-8";
+/*
+ * This stylesheet is separate from `style.css` to allow toggling dark mode with
+ * a button, with no duplication of information
+ */
+
+/* Set master 'dark-mode' colours */
+:root {
+    --colour-background: #011;
+    --colour-background-accent: #333;
+    --colour-text: #ccc;
+    --colour-links: #8bf;
+    --colour-scrollbar: #333;
+    --colour-rule-strong: #777;
+    --colour-rule-light: #222;
+    --colour-inline-code: #333;
+    --colour-warning: #900;
+}
diff --git a/pep_sphinx_extensions/pep_theme/static/style.css b/pep_sphinx_extensions/pep_theme/static/style.css
index a23a9ae600c..4b446d3dded 100644
--- a/pep_sphinx_extensions/pep_theme/static/style.css
+++ b/pep_sphinx_extensions/pep_theme/static/style.css
@@ -1,40 +1,22 @@
 @charset "UTF-8";
-/* Styles for PEPs
+/* Styles for PEPs */
 
-Colours:
-white:
-    background
-    footnotes/references vertical border
-#333
-    body text
-#888
-    blockquote left line
-    header breadcrumbs separator
-    link underline (hovered/focused)
-#ccc:
-    scrollbar
-#ddd
-    header bottom border
-    horizontal rule
-    table vertical border
-#eee:
-    link underline
-    table rows & top/bottom border
-    PEP header rows
-    footnotes/references rows
-    admonition note background
-#f8f8f8:
-    inline code background
-
-#0072aa:
-    links
-# fee:
-    admonition warning background
-
-*/
+/* Set master 'light-mode' colours (default) */
+:root {
+    --colour-background: white;
+    --colour-background-accent: #eee;
+    --colour-text: #333;
+    --colour-links: #0072aa;
+    --colour-scrollbar: #ccc;
+    --colour-rule-strong: #888;
+    --colour-rule-light: #ddd;
+    --colour-inline-code: #f8f8f8;
+    --colour-warning: #fee;
+}
 
 /* Set master rules */
 * {box-sizing: border-box}
+:root {color-scheme: light dark}
 html {
     overflow-y: scroll;
     -webkit-font-smoothing: antialiased;
@@ -46,8 +28,8 @@ html {
 }
 body {
     margin: 0;
-    color: #333;
-    background-color: white;
+    color: var(--colour-text);
+    background-color: var(--colour-background);
 }
 section#pep-page-section {
     padding: 0.25rem 0.25rem 0;
@@ -58,7 +40,7 @@ section#pep-page-section {
 p {margin: .5rem 0}
 
 /* Header rules */
-h1.page-title {
+h1 {
     line-height: 2.3rem;
     font-size: 2rem;
     font-weight: bold;
@@ -95,19 +77,19 @@ h6 {
 a,
 a:active,
 a:visited {
-    color: #0072aa;
-    text-decoration-color: #eee;
+    color: var(--colour-links);
+    text-decoration-color: var(--colour-background-accent);
     display: inline;
 }
 a:hover,
 a:focus {
-    text-decoration-color: #888;
+    text-decoration-color: var(--colour-rule-strong);
 }
 
 /* Blockquote rules */
 blockquote {
     font-style: italic;
-    border-left: 1px solid #888;
+    border-left: 1px solid var(--colour-rule-strong);
     margin: .5rem;
     padding: .5rem 1rem;
 }
@@ -130,7 +112,7 @@ code {
 }
 code.literal {
     font-size: .8em;
-    background-color: #f8f8f8;
+    background-color: var(--colour-inline-code);
 }
 pre {
     padding: .5rem .75rem;
@@ -147,7 +129,7 @@ dl dd {
 /* Horizontal rule rule */
 hr {
     border: 0;
-    border-top: 1px solid #ddd;
+    border-top: 1px solid var(--colour-rule-light);
     margin: 1.75rem 0;
 }
 /*Image rules */
@@ -187,14 +169,14 @@ sub {bottom: -0.25em}
 table {
     width: 100%;
     border-collapse: collapse;
-    border-top: 1px solid #eee;
-    border-bottom: 1px solid #eee;
+    border-top: 1px solid var(--colour-background-accent);
+    border-bottom: 1px solid var(--colour-background-accent);
 }
 table caption {
     margin: 1rem 0 .75rem;
 }
 table tbody tr:nth-of-type(odd) {
-    background-color: #eee;
+    background-color: var(--colour-background-accent);
 }
 table th,
 table td {
@@ -202,19 +184,20 @@ table td {
     padding: 0.25rem 0.5rem 0.2rem;
 }
 table td + td {
-    border-left: 1px solid #ddd;
+    border-left: 1px solid var(--colour-rule-light);
 }
 
 /* Breadcrumbs rules */
 section#pep-page-section > header {
-    border-bottom: 1px solid #ddd;
+    border-bottom: 1px solid var(--colour-rule-light);
 }
 section#pep-page-section > header > h1 {
     font-size: 1.1rem;
+    line-height: 1.4rem;
     margin: 0;
     display: inline-block;
     padding-right: .6rem;
-    border-right: 1px solid #888;
+    border-right: 1px solid var(--colour-rule-strong);
 }
 ul.breadcrumbs {
     margin: 0;
@@ -229,6 +212,17 @@ ul.breadcrumbs a {
     text-decoration: none;
 }
 
+/* Dark mode toggle rules */
+section#pep-page-section > header > button {
+    background: transparent url(colour_scheme.svg) 0/contain;
+    border: none;
+    cursor: pointer;
+    width: 1.2rem;
+    height: 1.2rem;
+    float: right;
+    translate: 0 50%;
+}
+
 /* Admonitions rules */
 div.note,
 div.warning {
@@ -237,10 +231,10 @@ div.warning {
     margin-bottom: 1rem;
 }
 div.note {
-    background-color: #eee;
+    background-color: var(--colour-background-accent);
 }
 div.warning {
-    background-color: #fee;
+    background-color: var(--colour-warning);
 }
 p.admonition-title {
     font-weight: bold;
@@ -253,8 +247,8 @@ dl.footnote {
     grid-template-columns: fit-content(30%) auto;
     line-height: 1.875;
     width: 100%;
-    border-top: 1px solid #eee;
-    border-bottom: 1px solid #eee;
+    border-top: 1px solid var(--colour-background-accent);
+    border-bottom: 1px solid var(--colour-background-accent);
 }
 dl.rfc2822 > dt, dl.rfc2822 > dd,
 dl.footnote > dt, dl.footnote > dd {
@@ -262,34 +256,42 @@ dl.footnote > dt, dl.footnote > dd {
 }
 dl.rfc2822 > dt:nth-of-type(even), dl.rfc2822 > dd:nth-of-type(even),
 dl.footnote > dt:nth-of-type(even), dl.footnote > dd:nth-of-type(even) {
-    background-color: #eee;
+    background-color: var(--colour-background-accent);
 }
 dl.footnote > dt {
     font-weight: normal;
-    border-right: 1px solid white;
+    border-right: 1px solid var(--colour-background);
 }
 
 /* Sidebar formatting */
-nav#pep-sidebar {
+#pep-sidebar {
     overflow-y: scroll;
     position: sticky;
     top: 0;
     height: 100vh;
     scrollbar-width: thin;  /* CSS Standards, not *yet* widely supported */
-    scrollbar-color: #ccc transparent;
+    scrollbar-color: var(--colour-scrollbar) transparent;
 }
-nav#pep-sidebar::-webkit-scrollbar {width: 6px}
-nav#pep-sidebar::-webkit-scrollbar-track {background: transparent}
-nav#pep-sidebar::-webkit-scrollbar-thumb {background: #ccc}
-nav#pep-sidebar > h2 {
+#pep-sidebar::-webkit-scrollbar {width: 6px}
+#pep-sidebar::-webkit-scrollbar-track {background: transparent}
+#pep-sidebar::-webkit-scrollbar-thumb {background: var(--colour-scrollbar)}
+#pep-sidebar > h2 {
     font-size: 1.4rem;
 }
-nav#pep-sidebar ul {
+#pep-sidebar ul {
     margin-left: 1rem;
 }
-nav#pep-sidebar ul a {
+#pep-sidebar ul a {
     text-decoration: none;
 }
+#toc-title {
+    font-weight: bold;
+}
 #source {
     padding-bottom: 2rem;
+    font-weight: bold;
+}
+
+.reference.external > strong {
+    font-weight: normal;  /* Fix strong links for :pep: and :rfc: roles */
 }
diff --git a/pep_sphinx_extensions/pep_theme/templates/page.html b/pep_sphinx_extensions/pep_theme/templates/page.html
index d47644a73c8..e3034448716 100644
--- a/pep_sphinx_extensions/pep_theme/templates/page.html
+++ b/pep_sphinx_extensions/pep_theme/templates/page.html
@@ -4,11 +4,14 @@
 <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>{{ title + " | "|safe + docstitle }}</title>
+    <meta name="color-scheme" content="light dark" />
+    <title>{{ title + " | peps.python.org"|safe }}</title>
     <link rel="shortcut icon" href="{{ pathto('_static/py.png', resource=True) }}"/>
     <link rel="stylesheet" href="{{ pathto('_static/style.css', resource=True) }}" type="text/css" />
     <link rel="stylesheet" href="{{ pathto('_static/mq.css', resource=True) }}" type="text/css" />
-    <link rel="stylesheet" href="{{ pathto('_static/pygments.css', resource=True) }}" type="text/css" />
+    <link rel="stylesheet" href="{{ pathto('_static/dark.css', resource=True) }}" type="text/css" media="(prefers-color-scheme: dark)" id="css-dark"/>
+    <link rel="stylesheet" href="{{ pathto('_static/pygments.css', resource=True) }}" type="text/css" media="(prefers-color-scheme: light)" id="pyg" />
+    <link rel="stylesheet" href="{{ pathto('_static/pygments_dark.css', resource=True) }}" type="text/css" media="(prefers-color-scheme: dark)" id="pyg-dark" />
     <link href="https://fonts.googleapis.com/css2?family=Source+Sans+Pro:ital,wght@0,400;0,700;1,400&display=swap" rel="stylesheet">
     <meta name="description" content="Python Enhancement Proposals (PEPs)"/>
 </head>
@@ -21,16 +24,19 @@ <h1>Python Enhancement Proposals</h1>
                 <li><a href="{{ pathto("pep-0000") }}">PEP Index</a> &raquo; </li>
                 <li>{{ title }}</li>
             </ul>
+            <button onClick="toggleColourScheme()"></button>
         </header>
         <article>
             {{ body }}
         </article>
         <nav id="pep-sidebar">
             <h2>Contents</h2>
+            <p id="toc-title">{{ title }}</p>
             {{ toc }}
             <br />
-            <strong id="source"><a href="https://github.com/python/peps/blob/main/{{sourcename}}">Page Source (GitHub)</a></strong>
+            <a id="source" href="https://github.com/python/peps/blob/main/{{sourcename}}">Page Source (GitHub)</a>
         </nav>
     </section>
+    <script src="{{ pathto('_static/colour_scheme.js', resource=True) }}"></script>
 </body>
 </html>
diff --git a/pep_sphinx_extensions/pep_theme/theme.conf b/pep_sphinx_extensions/pep_theme/theme.conf
index 8150ef720fa..bf410226aca 100644
--- a/pep_sphinx_extensions/pep_theme/theme.conf
+++ b/pep_sphinx_extensions/pep_theme/theme.conf
@@ -2,3 +2,4 @@
 # Theme options
 inherit = none
 pygments_style = tango
+pygments_dark_style = native