Licensing Question

[ksitu]

Hey ModalAI,
I was reading through your coding standards found here and I read that if we use either libmodal-pipe or libmodal-json libraries, we would fall under the LGPL V3 license.
libmodal-pipe, as I understand it, is the mechanism by which all of the sensor data makes its way into ROS. If we develop software in ROS (that makes use of the libmodal-pipe library), does that mean all of our SW would fall under LGPL?
Thanks,
Kenny

[Chad Sweet]

This is not legal advice, but Wikipedia has a nice writeup on LGPL that may be relevant to your question

GNU Lesser General Public License - Wikipedia

(en.wikipedia.org)

"Whether a work that uses an LGPL program is a derivative work or not is a legal issue. A standalone executable that dynamically links to a library through a .so, .dll, or similar medium is generally accepted as not being a derivative work as defined by the LGPL. It would fall under the definition of a "work that uses the Library". Paragraph 5 of the LGPL version 2.1 states:

A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License.

Essentially, if it is a "work that uses the library", then it must be possible for the software to be linked with a newer version of the LGPL-covered program. The most commonly used method for doing so is to use "a suitable shared library mechanism for linking". Alternatively, a statically linked library is allowed if either source code or linkable object files are provided."