LICENSEWARE
Python Software Foundation Rule

Modified Python redistributed in a product must be marked as modified

Catalog row in Vendor License Rules · Cited

Kind
Restriction
Statement
PSF Trademark Usage Policy, "The word Python": using the word "Python" when redistributing the Python programming language as part of a freely distributed application is allowed; if the standard version is modified this should be clearly indicated. Commercial distributions should contact the PSF for permission if the use is not covered by the nominative use rules. (page undated; as published on 2026-09-27)
Applies when
Redistributing standard or modified CPython inside a free or commercial application under the Python name.
Applies to
PSF trademarks; redistributed CPython.
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