[Libusb-win32-devel] Using libusb in a commercial application (LGPL / GPL)

[s***@agilent.com]

Hi everybody,

first I'd like to thank everyone involved for the great work on this project. Using the INF-Wizard and the examples, I had established communication to my USB instruments in almost no time.

Actually I'm not familiar with GPL/LGPL, but I read the licenses and tried to figure out, how to apply them to this project.

I am thinking about using libusb in a commercial (non-open-source) application and want to be sure that I am right about the licenses and terms.

In the mailing list archive I found a small number of messages regarding this topic, but they do not cover all my questions.

My understanding as of now is this: I may use programs and modules licensed under LGPL in commercial projects as long as I provide the required license and copyright information as well as the libusb source codes or a location where to download libusb source codes. My own work *does not* have to be licensed under LGPL or PGL in consequence.

[Xiaofan Chen]

Post by s***@agilent.com
Hi everybody,
first I’d like to thank everyone involved for the great work on this
project. Using the INF-Wizard and the examples, I had established
communication to my USB instruments in almost no time.

Thanks.

Post by s***@agilent.com
My understanding as of now is this: I may use programs and modules licensed
under LGPL in commercial projects as long as I provide the required license
and copyright information as well as the libusb source codes or a location
where to download libusb source codes. My own work *does not* have to be
licensed under LGPL or PGL in consequence.

I think this is right.

[s***@agilent.com]

Hi Xiaofan,



thanks for your quick response. Actually I tried to reply to your message, but I did only receive an email digest on the very first day after subscribing, so I copy/paste your message into this new one which will probably break up the email thread...

As far as I can see the installers are just executables *not* containing the
drivers (nor the library files). So together with my project's installer
(preferably as a part of it) I would have to provide the installer
executables as well as the library and sys files (drivers). So, wouldn't I
have to show a reference (copyright, license, sources) to the actual drivers
(and therefore the GPL license) as well, since they would be included in my
(overall) installer? And wouldn't that make the loosened restrictions of the
LGPL somewhat useless?

I am not so sure what you mean here. Are you incorporating the driver
installer to your own installer? Since it is covered by LGPL, you can treat
it the same as the library. You do have to show a reference to the libusb-win32
driver installer. But you do not need to publish your installer source --
I do not see it as a problem.

I'm afraid I don't see the clear difference between my software using API functions of the library (LGPL) and the library itself using functions of the drivers (GPL). Is this covered by the GNU License FAQ section "Can I release a non-free program that's designed to load a GPL-covered plug-in?". I didn't find FAQ information about something like using a driver (which I would not use from my own code, but through the library, so I think I'm fine here).

Obviously I got the meaning of the installers wrong. I thought one could run the installer_x86.exe/x64.exe to copy and register all required files to the windows system, so upon connecting the device, the drivers are present and selected automatically as long as there's no ambiguity with other drivers.

Not looking at the file sizes initially, I thought each of the above installer executables would contain everything required for using libusb on the target system, so the statement about the installers being licensed under LGPL made sense to me (being a bundle of the required files, with the bundle being licensed under LGPL). I would include that one/two installer file(s) to my overall installer, would add the appropriate copyright/license remarks and that should be it.

Then I found the executables do not contain the other files, so I would have to add all files to my own installer. By this I would also distribute the driver sys files in a certain way (Please forgive if "distribute" is the wrong term here. As mentioned before, I'm new to GPL terms and issues).

My concern is, that someone may read the statements from the license file, which state that the drivers are not LGPL but GPL. Since I would be giving them (the driver sys files) to users as part of my own installer, that may imply that certain GPL restrictions would apply to my own software as well. Is there a an obvious flaw in this view?

Thanks and best regards,
Sven

[Xiaofan Chen]

Post by s***@agilent.com
My concern is, that someone may read the statements from the license file,
which state that the drivers are not LGPL but GPL. Since I would be giving
them (the driver sys files) to users as part of my own installer, that may
imply that certain GPL restrictions would apply to my own software as well.
Is there a an obvious flaw  in this view?

I am not a GPL expert either. However, I think as long as you do not
change the driver itself, I do not see an issue here. I think you just
provide the link to the project webpage and state that the driver is
licensed under GPL.

If you are really concerned, please consult with a lawyer.