[sane-devel] Please give me some help to solve the license issues in using sane

[m. allan noah]

On 6/8/08, Olaf Meeuwissen <olaf.meeuwissen at avasys.jp> wrote:
> "m. allan noah" <kitno455 at gmail.com> writes:
>
>  > [snip]
>
> >>
>  >>  this means that the sane I/O facilities cannot be used. however
>  >>   it may be the cleanest thing.
>  >>
>  >>   that's similar to the epkowa way, which uses sane io facilities
>  >>   iirc?
>  >
>  > well, if epkowa dynamically links and uses sanei, then it is not using
>  > #3- it might be violating the license? Olaf- can you describe the
>  > mechanism?
>
> As anyone can infer from the epkowa sources, it dlopen()s interpreters
>  and passes two callbacks for USB I/O.  These callbacks ultimately call
>  the sanei_usb read and write functions.
>
>  The fact that epkowa dlopen()s instead of dynamically linking does not
>  make any difference license wise.  It is a convenience that allows for
>  the separate distribution of non-free plugins.
>  # Older versions of the epkowa backend would segfault without them!

dlopen v/s dynamic link certainly makes no difference from a license
perspective.

>  Also, the epkowa backend started out life as a clone of the epson
>  backend (around sane-1.0.3).  As a result, it relies on sanei to take
>  care of a few things (I/O, config, etc) and most of the epkowa backend
>  code is licensed under the GPL + SANE exception.  The bits that are
>  under a (slightly) different license, the epkowa_ip* files, are GPL +
>  an exception that is more restrictive than the SANE exception.

have you forgotten to mention the license on the closed source parts,
or are those the epkowa_ip* files?

>  WRT the possibility of violating the license, you've stated[1] that
>  the way in which components are combined (as in who uses who) does not
>  make a difference.

ahh, but that thread continued, with much more specific examples being
found in the FAQ. taking it out of context and calling it canon is a
bit much, particularly when the question at issue revolves mostly
around the exception, not the GPL itself.

> Also, in personal communication, you've mentioned
>  that you think the SANE exception is ambiguous enough to work in both
>  directions (even though the LICENSE file tries to clarify the issue).
>  So, I would think that the epkowa backend is in the clear here.

i would not use the word 'clear' to describe the situation. i think
epkowa backend is in very muddy waters. You are relying solely on the
ambiguity of the wording of the exception, and waving around your FSF
membership to make us feel better about it...

allan
-- 
"The truth is an offense, but not a sin"