PyPy

“it is still only a medium -fast language runtime, and it comes with a lot of costs and tradeoffs”

“PyPy's problem with slow startup is, in principle, easily fixable.”

“The common excuse is indeed wrong, as pypy proved.”

“PyPy wasn't great for me because its startup time interfered with the main usecase I wanted it for”

“their API for C based extensions differs enough that you cannot take a random shared library and load them into either.”

“The only reason the past couple major versions were released was due to a few small companies or individuals directly implementing the updates themselves.”

“GraalPy and PyPy are great technology achievements”

“Pypy does provide faster pure Python. Its a compatible implementation with JIT.”

“"C-extension issues" are not something you can just gloss over. They're a huge chunk of python usage.”

“Faster Python is right there and has been there for years.”

“PyPy performs valiantly compared to Cpython -- even better than LuaJIT.”

“it's several versions behind in support and, while it's not dead, it looks like it might be settling down for a rest.”

“The JIT would help everyone else more than removing the GIL, I wish PyPy became the reference implementation during 2.7”

“PyPy has been several times faster for many years.”

“I still think it is the sanest way to implement Python.”

“the warmup cost and compatibility tax are enough to keep most teams on the interpreter their deps target first”

“believing cpython folks benefit from seeing the pypy community prove Things Can Be Better”

“pypy only makes faster the type of python code which you absolutely should not write in python”

“I have used PyPy for years to beat the pants off CPython programs”

“is incompatible in a zillion critical ways, and is basically useless for large-scale development”

“PyPy is a toy for getting great numbers in benchmarks and demos, is incompatible in a zillion critical ways”

“it is lagging behind enough that it is falling out of the support window for a lot of libraries”

“cpyext is slow and incomplete and will waste your debugging time.”

“We have been using PyPy on core system component on production for like 10 years”

“9 months since the last major release definitely feels like a short time in which to declare time-of-death on an open source project”

“What annoys me is the name. Early morning it took me a moment to realise that PyPy is not PyPi”

“PyPy is a fantastic achievement and deserves far more support than it gets.”

“Being three major versions behind CPython is definitely not a great sign for the long-term viability of it.”

“I really like PyPy’s approach of using a Python dialect (RPython) as the implementation language, instead of C.”

“PyPy is really great in general speeding up Python by magnitudes of order.”

“There's an exact one to one algorithmic correspondence between an interpreted program and the compiled version of that.”

“have you tried PyPy? It's existed since 2007 and definitely improved over time.”

“it mostly works but because of some weird problem some library is broken and then they give up”

“It still runs 8.8x faster on pypy than on python 3.14”

“Pypy has much slower C interop than CPython, which I believe is part of the tradeoff.”

“If you want fast just use pypy and forget about cpython.”

“you give up a LOT of ecosystem just to get a still deeply unimpressive benchmark time”

“PyPy has existed for over half of Python's lifetime now.”

“Just changing the implementation of Python drops the runtime from ~16.5s to ~3.5s in my computer”

“The first thing to do when optimizing Python is to use a JIT (PyPy).”