f Python installation packages when arrived to the scene.  It appears
to be a side effect of Python having been around for so long, and having various lifetimes as more of a script engine
(as implemented), then to more of a structured language.  Over time, things change (<a class="reference external" href="https://packaging.python.org/discussions/wheel-vs-egg/">wheel vs egg</a>).  There appeared
to be version called the <a class="reference external" href="http://setuptools.readthedocs.io/en/latest/formats.h