[bastawhiz]

PyPy was released 17 years ago

Jython was released 22 years ago

IronPython was released 17 years ago

To date, no Python implementation has managed to hit all three:

1. Stay compatible with any recent, modern CPython version

2. Maintain performance for general-purpose usage (it's fast enough without a warmup, and doesn't need to be heavily parallelized to see a performance benefit)

3. Stayed alive

Which, frankly, is kind of a shame. But the truth of the matter is that it was a high bar to hit in the first place, and even PyPy (which arguably had the biggest advantages: interest, mindshare, compatibility, meaningful wins) managed to barely crack a fraction of a percent of Python market share.

If you bet on other implementations being the source of performance wins, you're betting on something which essentially doesn't exist at this point.

[eslaught]

Isn't PyPy up to 3.10 by now? At least that's what Homebrew reports to me.

PyPy seems pretty alive, all things considered, and for my code bases I've seen pretty dramatic speedups on the order of 2-5x. That's basically a no brainer unless I'm doing something with incompatible C extensions, which I think is the real Achilles heel of all of these alternative implementations.

[bastawhiz]

PyPy has definitely had the most success of all other implementations, but it still has a painful warmup period for many workloads. I can't imagine it's an effective option for anyone to install as the default Python implementation on their laptop, for instance. And for many, many years, it had almost no modern Python support (but I'm of course very glad to see it's slowly catching up).

It is encouraging for PyPy to see some influx of money in recent years. But I will continue to patiently wait for it to hit enough of a sweet spot of performance vs usability vs compatibility to see real adoption.