We want to distribute our (commercial closed-source) software as a virtual appliance.
Our preferred OS is Linux.
We do not want to violate the GPL, and we do not want to open source our own IP at this time.
Can we legally do this?
Or, do we need to use a an OS with a more permissive license (like BSD)?
(PS: I understand that I will need to ultimately seek the advice of a good lawyer.)
EDIT: Thanks to everyone for the comments.
Just the fact that your application is running on top of a GPL'd kernel in no way affects the licensing of your software. It really depends on what your software actually "links" to (for whatever definition "links" means for whatever language your software is written in).
Does your software link to the GPL kernel? Or any other GPL software?
As I understand it, the GPL is about freedom. You have the freedom to do what ever you want with the software, provided you pass those same freedoms on.
This means, yes, you are free to bundle GPL software/OS along with your commercial/closed source/proprietary software provided you pass the same freedoms of the GPL software onto your users.
In order to pass on those freedoms, if you make any changes to the GPL software, you must also GPL those changes, and you should make the source code of the GPL software available to any user of your bundle. but this in no way impacts any proprietary software you are providing along with the GPL'd OS.
If however your software links/compiles with/references anything GPL, that is another matter.
Like you said though, check with a lawyer if you want to know for certain.
The Linux kernel has a special version of the GPL that specifically allows this:
NOTE! This copyright does not cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does not fall under the heading of "derived work".
But yes, you should ask a lawyer :-).