diff --git a/doc/contributing.texi b/doc/contributing.texi
index b9260267fa..d12daa7ec3 100644
--- a/doc/contributing.texi
+++ b/doc/contributing.texi
@@ -786,6 +786,21 @@ for instance, the module python-dateutil is packaged under the names
 starts with @code{py} (e.g.@: @code{pytz}), we keep it and prefix it as
 described above.
 
+@quotation Note
+Currently there are two different build systems for Python packages in Guix:
+@var{python-build-system} and @var{pyproject-build-system}.  For the
+longest time, Python packages were built from an informally specified
+@file{setup.py} file.  That worked amazingly well, considering Pythons
+success, but was difficult to build tooling around.  As a result, a host
+of alternative build systems emerged and the community eventually settled on a
+@url{https://peps.python.org/pep-0517/, formal standard} for specifying build
+requirements.  @var{pyproject-build-system} is Guix's implementation of this
+standard.  It is considered ``experimental'' in that it does not yet support
+all the various PEP-517 @emph{build backends}, but you are encouraged to try
+it for new Python packages and report any problems.  It will eventually be
+deprecated and merged into @var{python-build-system}.
+@end quotation
+
 @subsubsection Specifying Dependencies
 @cindex inputs, for Python packages