Closed Source Program

A program that is not open source in some form, that is, a program whose source code cannot be obtained by users (including other developers).

LGPL

The LGPL agreement is a business friendly agreement.The implication here is that you can develop commercial programs under the LGPL license, as well as non-commercial closed source programs.However, it has some limitations.

Dynamic Links: You can publish your application in any form, commercial, non-commercial, open source, non-open source, whatever you want.

Static linking: Obligation to do the following:

1. You must state in your documentation that your program uses the LGPL library and that the library is released under the LGPL;
2. You must include a copy of the LGPL agreement with your application distribution, usually just that text file;
3. You must open all code that uses the LGPL library code (usually write a wrapper that wraps the LGPL library code so that only the wrapper code needs to be opened).
4. You must include object files ( .o etc.) for the rest of your application, or equivalent.Source code is not required.(Programs that use wrappers do not need to be open source, but the compiled intermediate files must be open sourced).

https://blog.51cto.com/devbean/313477

https://blog.51cto.com/devbean/394088