For my app that I'm about to release, I have used a bunch of 3rd party classes found for free online. I checked all the liscenses before using the code and each one said I could use the code commercially So now what I'm concerned about is do I have to give credit somewhere in my app to the creater of that class?

Also, I plan on having my app be free, but if in the future I charge for it, does that change things?

The most common license I see in an MIT License:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

The part I'm unsure about is:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

Is it enough for this license to be at the top of the class file embedded in the binary, or do I have to make it literally accessible to the user?

Of course I'm not asking for expert legal advice, but any help would be appreciated.

  • The title seems misleading: the question appears to be about contract terms (and thus contract law), not copyright law.
    – MSalters
    Jan 2, 2012 at 10:45
  • A lot of iOS apps put credits like this in the app's settings, under an About or Licensing entry.
    – mipadi
    Jan 6, 2012 at 20:10

2 Answers 2


This link might help you. If because it only says that the notice needs to be included in the software, putting in the source code should be fine.

Also, you do not really need to give credit to anyone else unless they ask you too (and if they wanted you to they'd make it evident when you download their code).

  • 1
    Thanks, that answer really helped, as did that link. And I always like to hear from fellow teenage developers
    – Andrew
    Jan 1, 2012 at 22:54
  • 3
    I would just like to suggest that it is always a good thing to give credit, even if you are not required to. If someone were using your code, wouldn't you appreciate getting credit?
    – JonnyBoats
    Jan 1, 2012 at 23:18

The following is true to most of the opensource licenses:

When you embed an opensource component into your product or your product can not function without it your product is considered a derivative work.

Some of these licenses are sticky, meaning if you create a derivative work and you publish it, then you have to also publish it as an opensource program (under the same license as the component). GPL is an example for this kind.

There are more permissive licenses which are not sticky, meaning you do not have to redistribute your program (and full source code) under the same license. For example MPL is not sticky.


If you are using their code you have to comply with their rules (the license the chose).

The MPL defines what is considered a derivative work based on files. For example if you copy-paste MPL-ed code into your source file, then that file falls under MPL too. GPL uses more lofty ideas which are open to interpretation.

  • Well why is that, I mean they opted to "give" away their software, with only that license, which in no way says I have to share my code; it just says they are sharing their code. Further, if I had just written the same code they did, how would it be any different. All they did was save me the time of doing it myself, which is nice, but doesn't seem like that should make the thousands of lines of my original code publicly available
    – Andrew
    Jan 1, 2012 at 22:49
  • @Andrew Please see edit.
    – vbence
    Jan 1, 2012 at 23:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.