DOC: Cleanup F2Py doc with reduced distutils info

doc/source/f2py/f2py.getting-started.rst

@@ -22,25 +22,28 @@ following steps:
 * F2PY compiles all sources and builds an extension module containing
   the wrappers.
 
-  * In building the extension modules, F2PY uses ``numpy_distutils`` which
-    supports a number of Fortran 77/90/95 compilers, including Gnu, Intel, Sun
-    Fortran, SGI MIPSpro, Absoft, NAG, Compaq etc. For different build systems,
-    see :ref:`f2py-bldsys`.
+  * In building the extension modules, F2PY uses ``meson`` and used to use
+    ``numpy.distutils`` For different build systems, see :ref:`f2py-bldsys`.
 
   * Depending on your operating system, you may need to install the Python
     development headers (which provide the file ``Python.h``) separately. In
     Linux Debian-based distributions this package should be called ``python3-dev``,
     in Fedora-based distributions it is ``python3-devel``. For macOS, depending
     how Python was installed, your mileage may vary. In Windows, the headers are
-    typically installed already.
+    typically installed already, see :ref:`f2py-windows`.
+
+.. note::
+
+   F2PY supports all the operating systems SciPy is tested on so their
+   `system dependencies panel`_ is a good reference.
 
 Depending on the situation, these steps can be carried out in a single composite
 command or step-by-step; in which case some steps can be omitted or combined
 with others.
 
-Below, we describe three typical approaches of using F2PY. These can be read in
-order of increasing effort, but also cater to different access levels depending
-on whether the Fortran code can be freely modified.
+Below, we describe three typical approaches of using F2PY with Fortran 77. These
+can be read in order of increasing effort, but also cater to different access
+levels depending on whether the Fortran code can be freely modified.
 
 The following example Fortran 77 code will be used for
 illustration, save it as ``fib1.f``:
@@ -298,3 +301,5 @@ the previous case::
 
   >>> print(fib3.fib(8))
   [  0.   1.   1.   2.   3.   5.   8.  13.]
+
+.. _`system dependencies panel`: http://scipy.github.io/devdocs/building/index.html#system-level-dependencies

doc/source/f2py/index.rst

@@ -5,13 +5,13 @@ F2PY user guide and reference manual
 =====================================
 
 The purpose of the ``F2PY`` --*Fortran to Python interface generator*-- utility
-is to provide a connection between Python and Fortran. F2PY is a part of NumPy_
-(``numpy.f2py``) and also available as a standalone command line tool.
-Originally created by Pearu Peterson, and older changelogs are in the
-`historical reference`_.
+is to provide a connection between Python and Fortran. F2PY distributed as part
+of NumPy_ (``numpy.f2py``) and once installed is also available as a standalone
+command line tool. Originally created by Pearu Peterson, and older changelogs
+are in the `historical reference`_.
 
-F2PY facilitates creating/building Python C/API extension modules that make it
-possible
+F2PY facilitates creating/building native `Python C/API extension modules`_ that
+make it possible
 
 * to call Fortran 77/90/95 external subroutines and Fortran 90/95
   module subroutines as well as C functions;
@@ -20,6 +20,14 @@ possible
 
 from Python.
 
+
+.. note::
+
+   Fortran 77 is essentially feature complete, and an increasing amount of
+   Modern Fortran is supported within F2PY. Most ``iso_c_binding`` interfaces
+   can be compiled to native extension modules automatically with ``f2py``.
+   Bug reports welcome!
+
 F2PY can be used either as a command line tool ``f2py`` or as a Python
 module ``numpy.f2py``. While we try to provide the command line tool as part
 of the numpy setup, some platforms like Windows make it difficult to
@@ -47,3 +55,4 @@ replace all calls to ``f2py`` mentioned in this guide with the longer version.
 .. _Python: https://www.python.org/
 .. _NumPy: https://www.numpy.org/
 .. _`historical reference`: https://web.archive.org/web/20140822061353/http://cens.ioc.ee/projects/f2py2e
+.. _Python C/API extension modules: https://docs.python.org/3/extending/extending.html#extending-python-with-c-or-c