Ruby and Python's standard implementations make use of a Global Interpreter Lock. Justin James explains the major advantages and downsides of the GIL mechanism.

Moore’s Law and Python’s flawed logic When language architects designed Python, they couldn’t conceive of a world where computers had more than one core. In the 1980s and 1990s, software engineers bet ...

The global interpreter lock is both a key component of the Python runtime and a major obstacle to multithreading. These are the plans to get around it or get rid of it.

A major criticism of the Python programming language is that it can't thread across cores. The reason is because of the CPython's Global Interpreter Lock (GIL). The inability to take advantage of more ...

Python 3.13: Better interactive shell and finally multithreading without GIL The new Python release features an interactive command line and allows the global interpreter lock to be deactivated.

For multi-threaded workloads, the lack of a GIL allows it to shine, blowing past the default interpreter with an 18x speedup by running 20 threads. Not too shabby.

Finally, the GIL itself was reworked somewhat in Python 3, with a better thread-switching handler. But all of its underlying assumptions — and limitations — remain.