Should I cite anything in my app for public domain/license?

Question

I am soon launching an Android app that uses some code and APIss from other developers or public domain etc, I believe they all have a public domain or similar public license.

1. SimpleNLG License
2. http://icon.shef.ac.uk/Moby/mwords.html (dead link, verified on 31.12.2020).
3. License and Commercial Use of WordNet

All of these feature a similar type of statement

"Permission to use, copy, modify and distribute this software and database and its documentation for any purpose and without fee or royalty is hereby granted, provided that you agree to comply with the following copyright notice and statements, including the disclaimer, and that the same appear on ALL copies of the software, database and documentation, including modifications that you make for internal use or for distribution."

I understand I don't owe anyone money or royalties from profits off my app (it's a paid app, if that's relevant), but do I cite these code sources anywhere? The part that confuses me is the "and that the same appear on ALL copies of the software". Am I supposed to have a copyright or reference to this domain or Api somewhere in my code or in my app? Do I just leave my app how it is and not worry about anything because it's license allows me usage or what?

Answer 1

There is a tremendous difference between public domain and the broad (nebulous) category of what you call "public licenses". Public domain means there is no copyright on the work, and you may deal with it virtually without restriction. An open-source or free-software license means that copyright does exist on the work, but the copyright owner will allow you to use it in specific ways. Use of the work outside that terms specified in the license is illegal.

Importantly, the MPL 1.1 is a weak copyleft license, meaning that if you modify any of the files in that project, your changes must also be licensed under the MPL. Because MPL has a weak copyleft, this does not extend to the rest of your project, though. If you use any component has a strong copyleft, like the GNU GPL, then that would require that your entire project be licensed under that license (e.g., the GPL, or whatever copyleft license it is).

Am I supposed to have a copyright or reference to this domain or Api somewhere in my code or in my app?

Yes, that is exactly correct. For instance, if you use Chrome, which is built on loads of open source software, you can see all their required notices in the chrome://credits/ URL. You need not obnoxiously force these notices onto your users every time they start up your app, but you must make them accessible somehow (e.g., via menu option).

Also critically, the Moby Words projects states in the README,

This documentation, software and/or database was developed and copyrighted by Grady Ward and is licensed, not sold, to you on a non-exclusive, non-transferable basis. The documentation, software and/or database and derivative works of this database may not be copied in whole or part except for archival purposes as provided by law. If you have purchased the commercial license, Grady Ward explicitly grants you the limited right to create and market data structures or knowledge bases derived this work without further payment of a license fee, as long as the purpose and effect of that data structure or knowledge base is other than re-distributing that Grady Ward data structure or database...

Unless you have purchased the commercial license, this seems quite clear that you are not allowed to redistribute the work within your application.