GPL licensed ROS software stack

asked 2018-04-23 09:58:37 -0500

asiron gravatar image

updated 2018-04-23 09:59:09 -0500

If a ROS software stack (that includes libraries, ROS nodes, messages and services, config files, etc) is GPL-licensed, then how much of this software stack can be used without forcing the GPL license on the whole project?

AFAIK modifying or linking with any library will force GPL license, but:

  1. Are the generated message headers also GPL-licensed ? Otherwise, every package using those message will be tainted with GPL :(
  2. As described in

    The ROS packaging and communication system allows for fine-grained licensing. Because nodes communicate via ROS messages, code from multiple nodes is not linked together. Thus the package provides a kind of "license boundary"

    However, the project requires some nodes to be running (e.g linking to them in *.launch files). Wouldn't it break the GPL clause ?

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However, the project requires some nodes to be running (e.g linking to them in *.launch files).

IANAL, but a launch file is like a shell script. That is not 'linking' in any understanding of the word.

gvdhoorn gravatar image gvdhoorn  ( 2018-04-23 10:13:29 -0500 )edit

That sounds great! What about message generated header files ? Are they GPL as well ?

asiron gravatar image asiron  ( 2018-04-23 11:10:06 -0500 )edit

It would probably help if you could make this a bit more concrete. There is very little GPL "in ROS". Are you thinking of specific packages?

gvdhoorn gravatar image gvdhoorn  ( 2018-04-23 11:11:41 -0500 )edit

If you look the transformation of "Message source code" (YAML?) to C++/Python message, then according to this, the C++/python message are still GPL :

lmathieu gravatar image lmathieu  ( 2018-04-23 12:01:40 -0500 )edit

IANAL again, but are IDL files considered code? It's a declarative spec at best.

@asiron: I'm not sure ROS Answers is the best venue for this sort of question. In any case, answers you get here are suggestions/hints/gut feelings. Any authoritative / conclusive answers would have to come ..

gvdhoorn gravatar image gvdhoorn  ( 2018-04-23 14:28:47 -0500 )edit

.. from lawyers probably. I don't believe we have any that frequent this forum.

gvdhoorn gravatar image gvdhoorn  ( 2018-04-23 14:29:11 -0500 )edit

It's the word "work" that do everything in the GPL I think, (but like gvdhoorn, I Am Not A Lawyer), but @asiron you will have better luck here : , people there knows a lot about GPL stuff (pretty rare on ROS).

lmathieu gravatar image lmathieu  ( 2018-04-24 01:58:47 -0500 )edit