Re: [boost] [SoC] License question

From: Jeff Garland (jeff_at_[hidden])
Date: 2007-03-20 10:48:18

Hugh Wimberly wrote:
> <introduction> Hi, I'm Hugh Wimberly, and I submitted a proposal for SoC. I
> was directed here to ask questions, and hope I'm not bothering
> anyone.</introduction>
> 
> For my project, I proposed to extend the regex library to use DFA-based
> regular expression matching, and essentially make it a hybrid matching
> engine that would be more predictably time-bounded. One of the reasons I
> proposed such an undertaking was that I know that there are other
> implementations that use this model; Plan 9 uses DFA-only regular expression
> matching, Tcl uses a very advanced hybrid model, and GNU awk uses almost
> exactly the model I proposed. These (and other) implementations are in
> general written in C and are all open-source. Since they're written in C, I
> couldn't directly use code anyway, but I'm a little worried about how much I
> can use them as a reference since most of them are licensed under the GPL,
> and Boost has an incredibly open license that isn't compatible with the GPL.
> My question is really just "what counts as using the code"--does writing
> similar code, knowingly using it as a reference infringe on copyright? If it

I'm not a lawyer.  That said, looking at a piece of related code for 
inspiration or understanding the algorithm does not infringe the copyright. 
If you start copying the code verbatim, in any way, then you've violated the 
copyright.  In addition, you'll have violated the rules of SoC.

> does, I think I have to amend my proposal, because I think it would take me
> much longer than I thought if I can't reference existing implementations.

I don't see a problem with doing some initial study to get the algorithms 
clear, however, research reports and other places might be better so you don't 
wind up with an 'accidental' infringement.  That is the unconscious use. That 
said, using these other implementations to test against, for example, would be 
a valuable and allowed use.

Jeff