The Python Imaging Library (PIL) is

Copyright © 1997-2011 by Secret Labs AB
Copyright © 1995-2011 by Fredrik Lundh

Pillow is the friendly PIL fork. It is

Copyright © 2010-2023 by Jeffrey A. Clark (Alex) and contributors.

Like PIL, Pillow is licensed under the open source HPND License:

By obtaining, using, and/or copying this software and/or its associated
documentation, you agree that you have read, understood, and will comply
with the following terms and conditions:

Permission to use, copy, modify and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appears in all copies, and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of Secret Labs AB or the
author not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permission.

SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR BE LIABLE FOR
ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
