While CPython 3.x is rock solid and shipped years ago - no argument there - both Pypy and Jython still lacks stable Python 3.x releases. That&#x27;s a major migration pain point.<p>It is hard trying to introduce Python 3 at a place that has systems that depend on both Cpython and Jython. Jumping between python 2 and 3 between projects is quite taxing mentally. And staying on python 2 only leaves me with a sense of lingering doom to say nothing of having to endure all the idiosyncrasies of python 2.x. I really enjoy the few moments when I can use Python 3.<p>It is perhaps easy to consider the 2 vs 3 debate over and done with for people who can just disregard Pypy and Jython entirely in their environment. I probably would think so myself had I not been so unfortunate to be the unwilling maintainer of solutions dependent on Jython right now.