PyPy

A fast, compliant alternative implementation of Python
Documentation (external link)
On average, PyPy 3.12 is about 4 times faster than CPython 3.11. We currently support Python 3.12, 3.11 and 2.7.
Advantages and distinct Features
Speed: thanks to its Just-in-Time compiler, Python programs often run faster on PyPy. (What is a JIT compiler?)
Memory usage: memory-hungry Python programs (several hundreds of MBs or more) might end up taking less space than they do in CPython.
Compatibility: PyPy is highly compatible with existing python code. It supports cffi and can run popular python libraries like twisted, and django. It can also run NumPy, Scikit-learn and more via a c-extension compatibility layer.
Stackless: PyPy comes by default with support for stackless mode, providing micro-threads for massive concurrency.
As well as other features.