I’m now thinking about problems of license and copyrights.
This library will be of the same type as SDL_image or any SDL-derived
- First question: Is the GPL V3 suitable for that purpose ?
I have not reviewed GPL v3, but I doubt it. SDL_image, SDL_mixer and
SDL itself are all released under the LGPL.
> How does copyright work, do I have to pay for this ? Is it
> an official status ?
In most cases, you simply declare the copyright. From Wikipedia:
In all countries where the Berne Convention standards apply,
copyright is automatic, and need not be obtained through official
registration with any government office. Once an idea has been reduced
to tangible form, for example by securing it in a fixed medium (such
as a drawing, sheet music, photograph, a videotape, or a computer
file), the copyright holder is entitled to enforce his or her
Am an not a lawyer (and neither is Wikipedia).
> Third question: Suppose I want to make a program available
> with a small fee (not SDL_Layer of course). I wonder
> what does the GNU foundation proposes. I've read in section
The GPL and LGPL do not specifically restrict selling software.
(I sell Tux Paint on CDROM via CafePress. I’ve seen numerous other people
selling it on eBay; both as a CDROM, and, mindbogglingly, as a download.)
Again, from Wikipedia:
The terms and conditions of the GPL are available to anybody receiving
a copy of the work that has a GPL applied to it (“the licensee”). Any
licensee who adheres to the terms and conditions is given permission
to modify the work, as well as to copy and redistribute the work or
any derivative version. The licensee is allowed to charge a fee for
this service, or do this free of charge. This latter point
distinguishes the GPL from software licenses that prohibit commercial
redistribution. The FSF argues that free software should not place
restrictions on commercial use, and the GPL explicitly states that GPL
works may be sold at any price.
You are encouraged to read and understand the licenses of software you
are using. You are especially encouraged to read and understand the
license under which you choose to release your OWN software.
4. Conveying Verbatim Copies.
from the GPL V3 that a person may ask or not for a fee to
redistribute either a verbatim or a modified version of a program.
(hope I understood well). I’m rather shocked to see that anybody
can then buy a copy of a game, let’s say 5$, and redistribute
a verbatim copy of it let’s say 15$ … I hope I misunderstood !
Nope, that’s how it works. Who is to say their cost to distribute is
$10 more? And what’s stopping the customer from avoiding them, and just
buying it for $5? (Well, except buyers obviously do not research as
much as they should.)
- Fourth question: I’d like people beeing able to provide modifications
to my projects, but I want to make sure things don’t go messy, let’s say
I want to keep a certain authority over the development roadmap.
Are there solutions for this ?
Choose a different license. With GPL, LGPL, and all other licenses
considered ‘open source’ (and no doubt other licenses NOT considered
’open source’), others can contribute, fork, etc.
If it were not for this, we wouldn’t have, for example, Cinepaint
(fork of Gimp used in professional films), X.org (fork of XFree86),
OpenSSH (fork of SSH1 when SSH2 was release as non-free software), etc.
- To finish, what is LGPL ?
The LGPL is the “GNU Lesser General Public License.”
(It was formerly called the “GNU Library General Public License”,
and you’ll see why.)
Once again, Wikipedia helps:
It was designed as a compromise between the strong-copyleft GNU
General Public License or GPL and permissive licenses such as the BSD
licenses and the MIT License. …
The LGPL places copyleft restrictions on the program itself but does
not apply these restrictions to other software that merely links with
the program. There are, however, certain other restrictions on this
The LGPL is primarily used for software libraries …
The main difference between the GPL and the LGPL is that the latter
can be linked to (in the case of a library, ‘used by’) a non-(L)GPLed
program, which may be free software or proprietary software. This
non-(L)GPLed program can then be distributed under any chosen terms if
it is not a derivative work.
This is how one can make commercial, ‘closed-source’ games and apps that
utilize SDL, for example. However, there’s an important freedom that the
people receiving the software get, with most LGPL software:
…it must be possible for the software to be linked with a newer
version of the LGPL-covered program. The most commonly used method for
doing so is to use “a suitable shared library mechanism for
linking”. Alternatively, a statically linked library is allowed if
either source code or linkable object files are provided.
However, I believe libSDL may be released under a dual license or
modified LGPL – I’ll let someone who knows confirm or deny.
(I am also not an SDL developer )
Anyway, good luck!On Fri, Jul 18, 2008 at 01:10:44PM +0000, julien CLEMENT wrote:
“Tux Paint” - free children’s drawing software for Windows / Mac OS X / Linux!
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