Python 3.13 is the latest stable release of the Python programming language, with a mix of changes to the language, the implementation and the standard library. The biggest changes include a new interactive interpreter, experimental support for running in a free-threaded mode (PEP 703), and a Just-In-Time compiler (PEP 744).
Suggestion: A new file extension
.pytto indicate its threaded code meant for the free-threaded mode enabled (no GIL). The current implementation is that there is a secondary binarypython3.13t, because its not compatible with regular Python interpreter.