Closes #25910: fix dead and permanently redirected links in the docs. Thanks to SilentGhost for the patch.
diff --git a/Doc/installing/index.rst b/Doc/installing/index.rst
index e955e33..e5b3165 100644
--- a/Doc/installing/index.rst
+++ b/Doc/installing/index.rst
@@ -43,7 +43,7 @@
   repository of open source licensed packages made available for use by
   other Python users
 * the `Python Packaging Authority
-  <https://packaging.python.org/en/latest/future.html>`__ are the group of
+  <https://www.pypa.io/en/latest/>`__ are the group of
   developers and documentation authors responsible for the maintenance and
   evolution of the standard packaging tools and the associated metadata and
   file format standards. They maintain a variety of tools, documentation
@@ -101,7 +101,7 @@
 .. seealso::
 
     `Python Packaging User Guide: Installing Python Distribution Packages
-    <https://packaging.python.org/en/latest/installing.html#installing-python-distribution-packages>`__
+    <https://packaging.python.org/en/latest/installing/>`__
 
 
 How do I ...?
@@ -118,8 +118,8 @@
 
 .. seealso::
 
-   `Python Packaging User Guide: Setup for Installing Distribution Packages
-   <https://packaging.python.org/en/latest/installing.html#setup-for-installing-distribution-packages>`__
+   `Python Packaging User Guide: Requirements for Installing Packages
+   <https://packaging.python.org/en/latest/installing/#requirements-for-installing-packages>`__
 
 
 .. installing-per-user-installation:
@@ -138,13 +138,13 @@
 aren't currently easy to install using ``pip`` directly. At this point in
 time, it will often be easier for users to install these packages by
 `other means
-<https://packaging.python.org/en/latest/science.html>`__
+<https://packaging.python.org/en/latest/science/>`__
 rather than attempting to install them with ``pip``.
 
 .. seealso::
 
    `Python Packaging User Guide: Installing Scientific Packages
-   <https://packaging.python.org/en/latest/science.html>`__
+   <https://packaging.python.org/en/latest/science/>`__
 
 
 ... work with multiple versions of Python installed in parallel?
@@ -174,7 +174,7 @@
    Once the Development & Deployment part of PPUG is fleshed out, some of
    those sections should be linked from new questions here (most notably,
    we should have a question about avoiding depending on PyPI that links to
-   https://packaging.python.org/en/latest/deployment.html#pypi-mirrors-and-caches)
+   https://packaging.python.org/en/latest/mirrors/)
 
 
 Common installation issues
@@ -207,11 +207,11 @@
 than needing to build them themselves.
 
 Some of the solutions for installing `scientific software
-<https://packaging.python.org/en/latest/science.html>`__
+<https://packaging.python.org/en/latest/science/>`__
 that is not yet available as pre-built ``wheel`` files may also help with
 obtaining other binary extensions without needing to build them locally.
 
 .. seealso::
 
    `Python Packaging User Guide: Binary Extensions
-   <https://packaging.python.org/en/latest/extensions.html>`__
+   <https://packaging.python.org/en/latest/extensions/>`__