using GPL licensed programs from other programs

[Ken Shaw]

G'day,

I've just got a question about the GPL. If you have a program like Xdelta,
that will compile to a command line program - but one that is protected by
the GPL - how can you use it?

Eg. lets just say you produced a visual basic windows program that made
calls to a command line GPL program, would the visual basic program be a
derivative work and thus subject to the GPL? i.e. - you're not linking to
teh GPL program, your just making command line calls - but you are including
the binary of the GPL program in your installer - how would this play out?

cheers,

ken

[boffy_b]

IANAL, but how I understand it is that as long as you are not adding any
of your code into Xdelta, none of your code has to be GPL'd, you can
re-distribute GPL'd software with proprietary ones on th same medium, in
th same package, no problem(just look at RedHat). Just make sure that
you don't put any code you want to keep proprietary into Xdelta(that is,
if you want to re-distribute it, you are free to do whatever you want if
you are just going to keep it on your own computer, but you sound like
you intend to distrbute.).

From what you say, your program sounds perfectly legal, I *believe*
that non-GPL apps can communicate with GPL ones at run-time(after all,
they do run on top of windows, talking to th API, etc.), nothing wrong
with that, but from what you say, it seems like what you have written a
VB front-end to Xdelta, and if this is th case, I don't see your
motivation in keeping it proprietary. It's not like it would be much use
on its own, and any prgrammer could whip up a GPL'd front-end for ther
favourite app quite quickly, but legally, I see no problem with what you
intend to do.

I repeat, I am *not* a lawyer, this is not to be taken as legal adive,
merely my opinion, yadda yadda...

boffy_b

Ken Shaw wrote:
G'day, I've just got a question about the GPL. If you have a program like Xdelta, that will compile to a command line program - but one that is protected by the GPL - how can you use it? Eg. lets just say you produced a visual basic windows program that made calls to a command line GPL program, would the visual basic program be a derivative work and thus subject to the GPL? i.e. - you're not linking to teh GPL program, your just making command line calls - but you are including the binary of the GPL program in your installer - how would this play out? cheers, ken

--
\//_
C ._)
| _| - "It is amazing what you can
| | accomplish if you do not
care who gets the credit." - Anon

[Paul DeGroot]

I'd concur with boffy_b, with the additional note that when you
redistribute the binary version of Xdelta you are probably required
under the GPL to also redistribute the original source code with full
copyright info. It's not a big deal (unless the source is a huge file
that won't fit on your distribution disk). Most of your customers will
probably never look at it, and anyone with an interest in Xdelta should
probably get the most recent version of the source code anyway.

Paul DeGroot
Licensing Analyst
Directions on Microsoft
Independent Research on Microsoft Strategies and Directions
www.directionsonmicrosoft.com


boffy_b wrote: IANAL, but how I understand it is that as long as you are not adding any of your code into Xdelta, none of your code has to be GPL'd, you can re-distribute GPL'd software with proprietary ones on th same medium, in th same package, no problem(just look at RedHat). Just make sure that you don't put any code you want to keep proprietary into Xdelta(that is, if you want to re-distribute it, you are free to do whatever you want if you are just going to keep it on your own computer, but you sound like you intend to distrbute.). From what you say, your program sounds perfectly legal, I *believe* that non-GPL apps can communicate with GPL ones at run-time(after all, they do run on top of windows, talking to th API, etc.), nothing wrong with that, but from what you say, it seems like what you have written a VB front-end to Xdelta, and if this is th case, I don't see your motivation in keeping it proprietary. It's not like it would be much use on its own, and any prgrammer could whip up a GPL'd front-end for ther favourite app quite quickly, but legally, I see no problem with what you intend to do. I repeat, I am *not* a lawyer, this is not to be taken as legal adive, merely my opinion, yadda yadda... boffy_b Ken Shaw wrote: G'day, I've just got a question about the GPL. If you have a program like Xdelta, that will compile to a command line program - but one that is protected by the GPL - how can you use it? Eg. lets just say you produced a visual basic windows program that made calls to a command line GPL program, would the visual basic program be a derivative work and thus subject to the GPL? i.e. - you're not linking to teh GPL program, your just making command line calls - but you are including the binary of the GPL program in your installer - how would this play out? cheers, ken