LICENSEWARE
Python Software Foundation Rule

Software incorporated in Python carries its own licences

Catalog row in Vendor License Rules · Cited

Kind
Restriction
Statement
History and License: some software incorporated into Python is under different licences, listed with the code they cover; the list of incorporated-software licences is described as incomplete. Components include Mersenne Twister, WIDE Project socket code, SipHash24, dtoa, expat (MIT-style), libffi (MIT-style), zlib, cfuhash, libmpdec (BSD-style), mimalloc (MIT), uvloop-derived asyncio code (MIT), pyzstd-derived bindings (3-Clause BSD) and the Unicode Character Database (Unicode License V3). Redistributors must carry each component's notices in addition to the PSF licence. (page undated; as published on 2026-09-27)
Applies when
Redistributing CPython source or binaries, or producing notices files and SBOMs for products that embed it.
Applies to
Python (CPython) source tree and binaries.
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