Subject: Re: GPL code contamination?
To: Oliver Korpilla <>
From: Michael <>
List: tech-kern
Date: 04/22/2005 19:48:44
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> If I were to look at GPL'ed code as the Linux kernel to get an inspiration
> how to implement a feature under NetBSD, but would neither cut/paste it n=
> try to adapt it to the NetBSD kernel, nor base my solution directly on it,
> would I contaminate the NetBSD kernel if I do something similar?
I don't think so - what's GPLed is a specific implementation, a piece of co=
de, not an algorithm.

> More specifically:
> Say I'd want to improve some aspect of the NetBSD scheduler, and reviewed
> the Linux scheduler in this respect, and implement a similar data structu=
> or algorithm within NetBSD without copying or breaking Linux' copyright,
> would it be acceptable? It would be a reimplementation at most, if not on=
> an influence on the final design?
If your implementation is reasonably different there shouldn't be a problem.

> Would it be legally problematic because of a GPL->BSD incompability? Would
> it be morally bad? Would it be accepted by the NetBSD community?
I've been using Linux code as documentation a couple of times, usually to s=
ee how they handle specific hardware conditions in drivers - most of the ti=
me the comments are all I need, copy&paste wouldn't be applicable since Net=
BSD and Linux are totally different at this level. If you use Linux code or=
 anything else as inspiration I think it's appropriate to credit the author=
s, especially if the algorithm in question is non-trivial as it seems to be=
 the case here. But better find a publicly available paper which describes =
the same thing, probably ask the authors for such a paper. Maybe I'm overly=
 paranoid but basing BSD-licenced work on GPLed code looks a little fishy t=
o me, even if your implementation is completely original - I'd feel better =
crediting a non-GPLed source.

have fun

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