Thanks a lot Ricardo,

Duden Mentor is proprietary software.

I found that wayback machine has a GNU licence.

Cambridge Dictionary and Oxford Advanced Learner's Dictionary have a: 
Mozilla Public License 2.0
Is that proprietäry software?


Gottfried


Am 13.11.22 um 21:04 schrieb Ricardo Wurmus:
> 
> Hi Gottfried,
> 
>> In Icecat I can download add-ons in this website:
>>
>> https://addons.mozilla.org/en-US/firefox/collections/11536848/webextensions/
>>
>> e.g. Duden-Mentor-Textprüfung
>> Oxford Advanced Learners Dictionary
>> Cambridge Dictionary
>> ImTranslator: Translator, Dictionary, TTS
>> Language Switch
> 
> There is an entry labelled “License” on the left side under “More
> information”.  This particular add-on, for example, is not free software
> as its license is “All Rights Reserved”.
>