Help me choose a software license

Question

My application reaches a pretty nice beta level, and I can publish it at some point. I have not decided which software license to use in my application. The application is under development. I bet it should be a question that every developer is thinking about at some point.

My software is more like a library, and here are some key factors in my case:

• It must be an open source license.
• It should be free for developers to use as a library for their applications.
• Developers can redistribute source code as part of their applications, modified or unmodified.
• The library can be used for closed source software.
• I want attribution / credit. Single line credit in the "Software Help" dialog box or somewhere in the section of their site is in order. Until it is wise for a third party to know which library was used to create the resulting software.
• You cannot allow a new project to start from my existing source code. I want people to be able to use it and even modify, but not clone, a new similar product in order to compete with my existing product.
• The license must state that I am not responsible for any damage.

Is there such a license? Will these requirements even comply with an open source license?

Answer 1

Cannot be allowed to start a new project from my source code.

Above contradicts the idea of ​​Open Source (which allows / encourages forking). Read more here: Which open source license does not have a fork

If you think you can refuse this requirement, the best choice is LGPL and additional requirements that people should give you a loan (you will need to determine what type of attribution / loan you want to use for different purposes)

As James said in a previous comment:

Forks are very rare

• It is very difficult to deploy a (large) project
• You can win more if there are forks - you can take good ideas from the forks and leave the bad. So the best feature / code decision will ultimately win (which is part of the Open Source idea).

Answer 2

You can find it according to your needs:

http://en.wikipedia.org/wiki/Comparison_of_free_software_licenses

In particular, I think that a lower public GPU license can satisfy the needs of your library. Keeping in mind that, like all (all?) Open source licenses, LGPL allows you to use forking.

http://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License

Answer 3

Deriving a new project from my existing source code should not be allowed. I want people to be able to use it and even modify, but not clone, a new similar product in order to compete against my existing product.

Ummm ... I have never heard this in an open source license, and I do not know any of this. How would you even say that? It will be very difficult to determine the difference between the plug and someone who took your code and just added the patch.

Can you think about it? Forks rarely happen, and when they do, they do not always compete. Talent, ideas and even code can freely move between the forks.

Answer 4

You need to talk with a lawyer, we are not lawyers and do not know your expression.

Preventing markup with open source licenses is tricky, says James.

For commercial applications, you may need dual licensing.

As far as I know, LGPL allows forks.