I have software with proprietary license. For some reasons I need an AGPL library (DLL). So, for including the AGPL licensed application (To manage license terms) I am using the following methods (I noted the below steps after searching so many sites and referring many advices):

Make a separate interface/ intermediate freeware application. Download that intermediate app in my main software when user clicks on the menu/ it is required at any point. This intermediate app will have option to download the AGPL (Or any open source libraries like LGPL etc.) application upon user's confirmation for its license terms.

I am not integrating the interface/intermediate application with my proprietary software. Instead, I use commandline to run the intermediate application from the main software.

Is the above mentioned method is legal and can I implement this on my software? Or is there any changes needed to my method of integration so that I can use the AGPL licensed app in my proprietary software?

  • 3
    Why can't you just open-source the entire program? What you describe is probably legal (as long as you license the "freeware" program under a GPL-compatible license and share its source code), but you won't have to worry about it at all if you release the complete source code.
    – habs
    Apr 20, 2018 at 7:40
  • I can not make the whole project open-source but i can make the intermediate freeware application as open source. Apr 20, 2018 at 9:48
  • You you mean “Free Software”? “freeware” is not defined any ware. It was used in the 1980's to mean many things. Apr 24, 2018 at 15:29
  • 2
    Note it is not a matter of distribution. GPL allows distribution with proprietary software. However if it becomes part of the software, then it is a copy-right infringement, unless the resultant work is also GPL. Apr 24, 2018 at 15:30

1 Answer 1


Using a command line interface to GPL code is the normal approach in this situation. So your approach is generally fine. But you are overcomplicating this: you don't need to download on demand, and you don't have to force users to read the GPL license.

  • The AGPL is equivalent to the GPL when the software runs locally. The LGPL is also equivalent to the GPL, except that you can link with LGPL libraries without a command line wrapper. Therefore, the rest of this answer will only mention the GPL.

  • The GPL explicitly does not require that users accept the license. Accepting the license is only necessary if you modify or distribute the GPL software. I.e., your acceptance and not your users' acceptance is necessary.

  • It is equivalent whether you download the GPL software on demand or bundle it with your proprietary software. As long as they are clearly different programs and you comply with the GPL terms, the GPL allows this “aggregation”: “Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.”

  • If a proprietary program uses the command line interface of a GPL program, the GPL won't generally apply to the proprietary program. So creating a wrapper program for a GPL library will, in general, sufficiently isolate your proprietary program.

  • However, the wrapper program does fall under the GPL. A “freeware” wrapper is not sufficient. You can only distribute the wrapper if you comply with the GPL terms, such as offering the source code. The details here depend on the exact GPL version.

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