[cc-licenses] Does BY-SA do what I think it does?

Terry Hancock hancock at anansispaceworks.com
Wed Jun 7 04:53:28 EDT 2006


Cameron McCormack wrote:
>  I wonder what the implications are of changing to the LGPL from
>  BY-SA. Must all future revisions of my library also be available for
>  use under BY-SA, since it was at one time distributed under that
>  licence? Are there any issues with it being available under both
>  BY-SA and LGPL?

Technically all the versions you released under the By-SA will still
be under that license.  You may of course, re-release them all under
LGPL, so they will be dual-licensed.

No one will actually care, because the LGPL is the much more
common and compatible license.

>  I suppose it would be ideal if I can just switch to LGPL and forget
>  the BY-SA altogether.

You pretty much can -- the fact that some of the stuff was previously
(and therefore still) available under By-SA is kind of a footnote.

Three caveats worth mentioning:

I've assumed the work is entirely yours. If you have already received
contributions under the By-SA, you probably need the authors
permission to switch the license (that is, to switch the license on their
contributions, you see).

Obviously, someone could still choose to build a By-SA version based
on your earlier, By-SA work.  Theoretically. In practice, probably no
one would want to do that (anything they would want to do with the
By-SA they can do with LGPL, and probably a few more things).

The By-SA isn't necessarily an "open source" license, but the LGPL
(and GPL) are -- that is to say, they explicitly require source code
to be available.  I seriously doubt that's a problem, but it is a difference
in the licenses (technically, under the By-SA you could do a binary-patched
version of the software, without including the source for the patch --
again, this is extraordinarily unlikely behavior, since it would be a
pain for all involved).

I doubt any of those will be problems for you, but that's about all
I can think of that could go wrong with switching the license.

Cheers,
Terry


-- 
Terry Hancock (hancock at AnansiSpaceworks.com)
Anansi Spaceworks http://www.AnansiSpaceworks.com




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