The VirtualBox Base Package is licensed under the GNU General Public License, version 2.
My company is distributing software that runs on an Ubuntu system within a VirtualBox VM. We have not modified VirtualBox in any way and the install file and process is totally separate from our software.
We were led to believe that it would be OK to distribute our software to multiple clients without them needing a license for VBox, but recently this has been called into question and we want to confirm that what we're doing is legal.
Technically, the software itself is free and we charge clients for each file/document that they generate using the software.
Is it legal for us to charge for our software? If not, does it make a difference that we charge for files rather than the software itself?
Do we need to make our source code available to users if we are using VBox under the GPL? This is almost certainly not acceptable to us as it is proprietary software that we do not want to make available to others.
If we will run into licensing issues, I wonder if we could get around them by having the client install their choice of Virtualization software (we would heavily recommend VBox). We would install our VM image on their virtualization software. Since we are not involved at all in the distribution of VBox, does that let us off the hook for any licensing concerns?
Unfortunately I'm not very knowledgeable on licensing practices. I've been doing some research on the GNU GPL v2, but some things I read lead me to believe we're in the clear and others seem to suggest we're not.
If anyone could shed some light on this it would be greatly appreciated!