> IMO, Python 2 is a genericized trademark like Kleenex at this point.
Kleenex is often used to refer to facial tissue, regardless of manufacturer of the facial tissue.
Python 2 is used to refer to one of the releases of the CPython 2 interpreter, most often the latest release, with earlier releases typically referred to with their first point (e.g. "2.6" as I've seen elsewhere in this thread). People rarely refer to Pypy or Jython as "Python 2", at least in my experience. They may refer to compatibility with a point release of the official CPython.
For example, Pypy describes itself as with the following:
> PyPy implements Python 2.7.13 and 3.6.9. It supports all of the core language, passing the Python 2.7 test suite and most of the 3.6 test suite.
They're not saying PyPy is Python 2, rather that it implements the programming language represented by point release Python 2.7.13. Elsewhere, they talk about compatibility with Python. Nowhere do the PyPy developers refer to their product as "Python 2".
