Update manylinux tags section

source/specifications/platform-compatibility-tags.rst

@@ -5,24 +5,90 @@
 Platform compatibility tags
 ===========================
 
-The platform compatibility tagging model used for ``wheel`` distribution is
-defined in :pep:`425`.
+Platform compatibility tags allow build tools to mark distributions as being
+compatible with specific platforms, and allows installers to understand which
+distributions are compatible with the system they are running on.
+
+The platform compatibility tagging model used for the ``wheel`` distribution
+format is defined in :pep:`425`.
+
+Platform tags for Windows
+-------------------------
+
+The scheme defined in :pep:`425` covers public distribution of wheel files to
+systems running Windows.
+
+Platform tags for macOS (Mac OS X)
+----------------------------------
+
+The scheme defined in :pep:`425` covers public distribution of wheel files to
+systems running macOS (previously known as Mac OS X).
+
+Platform tags for common Linux distributions
+--------------------------------------------
 
 .. _manylinux:
 
-Manylinux tags
-==============
+The scheme defined in :pep:`425` is insufficient for public distribution of
+wheel files (and \*nix wheel files in general) to Linux platforms, due to the
+large ecosystem of Linux platforms and subtle differences between them.
+
+Instead, :pep:`513` defines the ``manylinux`` standard, which represents a
+common subset of Linux platforms, and allows building wheels tagged with the
+``manylinux`` platform tag which can be used across most common Linux
+distributions.
+
+There are multiple iterations of the ``manylinux`` specification, each
+representing the common subset of Linux platforms at a given point in time:
+
+* ``manylinux1`` (:pep:`513`) supports ``x86_64`` and ``i686``
+  architectures, and is based on a compatible Linux platform from 2007.
+* ``manylinux2010`` (:pep:`571`) supports ``x86_64`` and ``i686``
+  architectures. and updates the previous specification to be based on a
+  compatible Linux platform from 2010 instead.
+* ``manylinux2014`` (:pep:`599`) adds support for a number of
+  additional architectures (``aarch64``, ``armv7l``, ``ppc64``, ``ppc64le``,
+  and ``s390x``) and updates the base platform to a compatible Linux platform
+  from 2014.
+
+In general, distributions built for older versions of the specification are
+forwards-compatible (meaning that ``manylinux1`` distributions should continue
+to work on modern systems) but not backwards-compatible (meaning that
+``manylinux2010`` distributions are not expected to work on platforms that
+existed before 2010).
+
+Package maintainers should attempt to target the most compatible specification
+possible, with the caveat that the provided build environment for
+``manylinux1`` has reached end-of-life, and the build environment for
+``manylinux2010`` will reach end-of-life in November 2020 [#]_, meaning that
+these images will no longer receive security updates.
+
+Manylinux compatibility support
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. Note::
+   The ``manylinux2014`` specification is relatively new and is not yet widely
+   recognised by install tools.
+
+The following table shows the minimum versions of relevant projects to support
+the various ``manylinux`` standards:
+
+==========  ==============  =================  =================
+Tool        ``manylinux1``  ``manylinux2010``  ``manylinux2014``
+==========  ==============  =================  =================
+pip         ``>=8.1.0``     ``>=19.0``         ``>=19.3`` [#]_
+auditwheel  ``>=1.0.0``     ``>=2.0.0``        ``>=3.0.0`` [#]_
+==========  ==============  =================  =================
+
+Platform tags for other \*nix platforms
+---------------------------------------
 
-The scheme defined in :pep:`425` is insufficient for public distribution
-of Linux wheel files (and \*nix wheel files in general), so the *manylinux*
-platform tags were defined, to allow providing wheels for many common Linux
-distributions. See :pep:`513` for more about how this works.
+The scheme defined in :pep:`425` is not generally sufficient for public
+distribution of wheel files to other \*nix platforms. Efforts are currently
+(albeit intermittently) under way to define improved compatibility tagging
+schemes for AIX and for Alpine Linux.
 
-* ``manylinux1`` is defined in :pep:`513`, for x86_64 and i686 architectures.
-* ``manylinux2010`` is defined in :pep:`571`, for x86_64 and i686 architectures.
-  It is based on a platform from 2010, whereas ``manylinux1`` is based on a
-  platform from 2007. This means that ``manylinux2010`` packages are easier to
-  create, but not compatible with some older systems where ``manylinux1``
-  packages would work.
 
-  ``manylinux2010`` is not yet widely recognised by install tools.
+.. [#] https://wiki.centos.org/About/Product
+.. [#] Not yet released.
+.. [#] Not yet released.