While working on an attempt to create a macOS .app version of Guiguts, I did some analysis on this question. I am not a lawyer, but my research turned up no concerns about licensing for the various things I planned to bundle.

The below is from my notes. I've taken a few things out because some were Perl itself, or Perl modules, and wouldn't apply to a Python project.

Licenses found

• Homebrew: BSD-2-Clause
• Homebrew (vendored): MIT
• berkeley-db: AGPL-3.0-only
• [email protected]: OpenSSL
• ca-certificates: MPL-2.0
• gdbm: GPL-3.0-or-later
• Guiguts: GPL 2 (only?) - may need relicensing. see below.
• bookloupe: GPL 2 (only?) - may need relicensing. see below.
• aspell: LGPL-2.1-only
• tidy-html5: Zlib
• open-sp: can't determine? all the links are 404. seems super super abandoned.
• jeebies: GPL v2+
• ebookmaker: GPL 3
• Python 3 (for ebookmaker): PSF license
• Cairo (for ebookmaker): LGPL-2.1 or MPL-1.1
• Noto Sans font: SIL Open Font License
• Java: no, I'm not dealing with this. user can do this on their own if they want.

The GPL is the most viral of all these licenses.

BSD-2-Clause

https://opensource.org/licenses/BSD-2-Clause

• must include the license in either source or binary distribution

MIT

https://opensource.org/licenses/MIT

• must include the license in either source or binary distribution

AGPL-3.0

https://opensource.org/licenses/AGPL-3.0

• must include the license in either source or binary distribution
• must disclose source
• must include install instructions

Dual OpenSSL / SSLeay license

https://www.openssl.org/source/license-openssl-ssleay.txt

• must include the license in either source or binary form
• must include this notice: "This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/)"
• If this package is used in a product, Eric Young should be given attribution as the author of the parts of the library used.

MPL 2.0

https://opensource.org/licenses/MPL-2.0

• Must include the license in source or binary form
• must link to source code for original

LGPL 2.1

https://opensource.org/licenses/LGPL-2.1

• must include original source, or link clearly to where to obtain it
• must include the copyright/license
• must give prominent notice that LGPL'd software is being used

Zlib

https://opensource.org/licenses/Zlib

• must include copyright & license

SIL Open Font License

http://scripts.sil.org/OFL

This seems to be a very liberal license with almost no requirements other than you can't sell the fonts as a product themselves; only a product that includes them.

PSF license

https://docs.python.org/3/license.html

Says it's GPL compatible. Doesn't seem to be a notification requirement but it's probably smarter to just include a copy of the license.

BUT:
There are other bundled licenses; some do require notice. See the list here:
https://docs.python.org/3/license.html#otherlicenses

GNU General Public License 2.0

https://opensource.org/licenses/GPL-2.0

• must include/link to original
• include copyright & license

GNU General Public License 3.0

https://opensource.org/licenses/GPL-3.0

• must link to/include original
• must disclose source
• must include license/copyright info
• must include install instructions

On multiple licensing with GNU GPL

https://en.wikipedia.org/wiki/GNU_General_Public_License#Compatibility_and_multi-licensing

License TODO

relicense Guiguts as GPL 2.0 "or later"?

No need: guiguts.pl right at top of file has the "or later"!

relicense bookloupe as GPL 2.0 "or later"?

No need: the license embedded in the code files has "or later"!

from guiguts-py.

Just to clarify - my project was planning to bundle / distribute all of this stuff. How much of it matters will depend on how the code is packaged (or not).

from guiguts-py.