License

Zhou_Hao · April 12, 2006, 5:20am

I have a question regarding with the license. Do I need to pay or I have to
submit my source code if I only use SDL as a library in my commercial game?

Richard_Hancock · April 12, 2006, 6:25am

Neither. Just use the linking library (.lib or .a depending on linker) and
provide access to the source of the version of SDL you used. Although
donations are always accepted. Check out the license file to make sure
everything is in compliance. But I believe that is all you need to do.

HTH,
RichardOn 4/12/06, Zhou Hao <zhou.hao.27 at gmail.com> wrote:

I have a question regarding with the license. Do I need to pay or I have
to
submit my source code if I only use SDL as a library in my commercial
game?

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

–
Richard J Hancock
RJH Computers
http://www.rjhcomputers.com

atrix2 · April 12, 2006, 6:28am

If you don’t statically link sdl into your game then you don’t need to do
anything.

If you do statically link sdl into your game, you need to provide the
sourcecode to your game to the people using your game, or some other method
for them to relink your game with sdl.

Basically, the user should just have the power to modify sdl or grab a
version they want to use, and relink your game with their chosen version of
sdl.

The easiest way is to just dynamically link to sdl so that they can drop in
new DLLs if they want to.> ----- Original Message -----

From: sdl-bounces+atrix2=cox.net@libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Zhou Hao
Sent: Tuesday, April 11, 2006 10:20 PM
To: sdl at libsdl.org
Subject: [SDL] License

I have a question regarding with the license. Do I need to pay or I have to
submit my source code if I only use SDL as a library in my commercial game?

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

Bill_Kendrick · April 12, 2006, 8:15am

FYI:

"Frequently Asked Questions: Licensing"
http://www.libsdl.org/faq.php?action=listentries&category=8

Since the LGPL still seems to be confusing to people, it may make sense
for Sam (or someone who can muck with the website) to add some more explicit
answers.

It MIGHT even be useful to, in future releases of SDL, include a preamble
to the license itself (inside COPYING.txt) that directs people to the FAQ.

Just a suggestion

-bill!On Wed, Apr 12, 2006 at 05:20:16AM +0000, Zhou Hao wrote:

I have a question regarding with the license. Do I need to pay or I have to
submit my source code if I only use SDL as a library in my commercial game?

Simon3 · April 13, 2006, 3:58am

I found any questions regarding laws and licenses seem to frighten
people a lot, specially when those person’s ignorance is combined with
the “RTFM” attitude from the guys who understand…

I feel it would be interesting to have a place to read more about the
license, a site that would be written in a vulgar english that
everybody can understand, providing examples of what somebody can do.
Something more visual, like here’s how you can distribute your
software, and here’s what your directory should look like (with the
License.txt, all dlls, etc…).

This might be out of topic, but I still feel 1) it’s directly related
to SDL as everybody at some time has questions regarding the license
and 2) I’m sure out of the SDL community there are lots of people that
have the exact same questions.

Just an idea like that…
Simon

atrix2 · April 13, 2006, 4:17am

Hey I second that, I’m pretty sure I know how to satisfy the license
requirements but it was some time before I had it down, something like that
sure woulda helped! :P> ----- Original Message -----

From: sdl-bounces+atrix2=cox.net@libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Simon
Sent: Wednesday, April 12, 2006 8:58 PM
To: A list for developers using the SDL library. (includes SDL-announce)
Subject: Re: [SDL] License

I found any questions regarding laws and licenses seem to frighten
people a lot, specially when those person’s ignorance is combined with
the “RTFM” attitude from the guys who understand…

I feel it would be interesting to have a place to read more about the
license, a site that would be written in a vulgar english that
everybody can understand, providing examples of what somebody can do.
Something more visual, like here’s how you can distribute your
software, and here’s what your directory should look like (with the
License.txt, all dlls, etc…).

This might be out of topic, but I still feel 1) it’s directly related
to SDL as everybody at some time has questions regarding the license
and 2) I’m sure out of the SDL community there are lots of people that
have the exact same questions.

Just an idea like that…
Simon

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

Daniel_K_O · April 13, 2006, 6:23am

Simon escreveu:

I found any questions regarding laws and licenses seem to frighten
people a lot, specially when those person’s ignorance is combined with
the “RTFM” attitude from the guys who understand…

I think it’s hard to be any simpler than
http://www.libsdl.org/license.php without leaving out important details.

But I think the main page should at least mention something about the
licensing. It currently only mentions features, platforms and language
bindings. Maybe adding the word “Free” (linking to the license.php page)
somewhere could be a good idea.—
Daniel K. O.

atrix2 · April 13, 2006, 8:18am

I like the FAQ idea for the license (or for sdl in general)

Q. Can I use SDL in a commercial game?
A. Yes you can, if you link statically (include the sdl source inside your
game when you compile) you have to make your source code available to the
public. If you link dynamically (via .dll’s, .so’s or using other dynamic
linking devices) then you do not need to do anything.

Q. If I use SDL commercially do I owe royalties to SDL?
A. No you do not but you can donate here

Something like that would be pretty nice, so long as people actually look at
it :P> ----- Original Message -----

From: sdl-bounces+atrix2=cox.net@libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Daniel K. O.
Sent: Wednesday, April 12, 2006 11:24 PM
To: A list for developers using the SDL library. (includes SDL-announce)
Subject: Re: [SDL] License

Simon escreveu:

I found any questions regarding laws and licenses seem to frighten
people a lot, specially when those person’s ignorance is combined with
the “RTFM” attitude from the guys who understand…

I think it’s hard to be any simpler than
http://www.libsdl.org/license.php without leaving out important details.

But I think the main page should at least mention something about the
licensing. It currently only mentions features, platforms and language
bindings. Maybe adding the word “Free” (linking to the license.php page)
somewhere could be a good idea.

Daniel K. O.

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

mal_content · April 13, 2006, 9:09am

I like the FAQ idea for the license (or for sdl in general)

Q. Can I use SDL in a commercial game?
A. Yes you can, if you link statically (include the sdl source inside your
game when you compile) you have to make your source code available to the
public.

Shouldn’t that be ‘object files’ instead of ‘source code’? You don’t need
to supply source code in order to be able to re-link your program.On 4/13/06, Alan Wolfe wrote:

If you link dynamically (via .dll’s, .so’s or using other dynamic
linking devices) then you do not need to do anything.

Q. If I use SDL commercially do I owe royalties to SDL?
A. No you do not but you can donate here

Something like that would be pretty nice, so long as people actually look at
it

Gerry_Jo_Jellestad · April 13, 2006, 9:20am

If you do put up a FAQ, at least make sure the answers are correct. You
do not have to make your source code available even if you statically link
SDL. What you have to do is provide a way for people to replace the
linked SDL library. This can be done in several ways:

Link dynamically
Provide both dynamic and static (but otherwise identical) executables
Only static, but provide source code
Only static, but provide relinkable object files
Only static, but provide a way to override the statically linked SDL
More (read the LGPL)

Oh, and IANAL, etc.

GerryOn Thu, 13 Apr 2006 10:18:50 +0200, Alan Wolfe wrote:

A. Yes you can, if you link statically (include the sdl source inside
your
game when you compile) you have to make your source code available to the
public. If you link dynamically (via .dll’s, .so’s or using other
dynamic
linking devices) then you do not need to do anything.

Peter_Mulholland · April 13, 2006, 5:30pm

Hello Zhou,

Wednesday, April 12, 2006, 6:20:16 AM, you wrote:

ZH> I have a question regarding with the license. Do I need to pay or I have to
ZH> submit my source code if I only use SDL as a library in my commercial game?

To answer simply, you do not have to pay or provide source code as
long as you dynamically link to SDL. This means using a DLL, dylib, or
.so (choose as appropriate for your OS)–
Best regards,
Peter mailto:@Peter_Mulholland

Bill_Kendrick · April 13, 2006, 7:17pm

And more correctly, there’s nothing preventing one from creating
something that’s both commercial, and includes source-code
(with whatever kind of nasty license preventing them from redistributing
the source… think other software industries, not games…)

So specifically, it might be better to ask:

Q. Can I use SDL in a program without providing my source code?
(e.g., a commercial game)

shrugOn Thu, Apr 13, 2006 at 10:09:15AM +0100, mal content wrote:

On 4/13/06, Alan Wolfe wrote:

I like the FAQ idea for the license (or for sdl in general)

Q. Can I use SDL in a commercial game?
A. Yes you can, if you link statically (include the sdl source inside your
game when you compile) you have to make your source code available to the
public.

Shouldn’t that be ‘object files’ instead of ‘source code’? You don’t need
to supply source code in order to be able to re-link your program.

–
-bill!
bill at newbreedsoftware.com
http://www.newbreedsoftware.com/

slouken · April 14, 2006, 5:56am

I like the FAQ idea for the license (or for sdl in general)

How’s this?
http://www.libsdl.org/faq.php?action=listentries&category=8

-Sam Lantinga, Senior Software Engineer, Blizzard Entertainment

Julien_Clement1 · June 25, 2008, 9:30am

Well,

I see this thread has a lot of success ^^
And personnally I learn quite a lot.

My first motivation for static linking was to ease an end user task in
installing the game/software. But it’s not a reasonable ground afterwards,
because commercial games just provide DLLs/dylibs/so packed with the
application and copy them in a target directory of the system. So, if I may,
forget my question concerning static linkage.

Back to license problems if you don’t mind. Imagine tomorrow I’m very satisfied
with a program and I want to make it a shareware. It is dynamically linked with SDL,
and some derivates like SDL_image, SDL_net, and SDL_mixer.
I want to make this game paying.

What are the possible problems I may encounter:

When the game is open-source
When the game is *not* open-source

Many thanks

Julien

----- Message d’origine ----De : Hajd? Zolt?n
? : A list for developers using the SDL library. (includes SDL-announce)
Envoy? le : Mercredi, 25 Juin 2008, 11h15mn 50s
Objet : Re: [SDL] Static link

Hello,

It is not the time overhead, but the storage space: even for really
tiny applications, you have to include megabytes of dlls when using
images, audio, etc.

Z.

On Jun 24, 2008, at 8:57 PM, Edward Cullen wrote:

In other words; don’t link statically unless you’re on an embedded
platform that either doesn’t support dynamic linking or you need
to save the overhead of dynamic linking (which ONLY applies to
embedded platforms).

  _____________________________________________________________________________

Envoyez avec Yahoo! Mail. Une boite mail plus intelligente http://mail.yahoo.fr

Peter_Mackay · June 25, 2008, 9:47am

I don’t think you’d encounter any problems, regardless of open/closed
source, as the user would still be able to use their own SDL DLLs with
your game, just by swapping the ones you’ve provided with the ones
they want to use.

Am I right in thinking that the dual license is really for the
situations where the user can’t possibly replace the library,
therefore the developer can’t satisfy the LGPL? That is, on closed
platforms such as Microsoft, Sony and Nintendo consoles.

Peter

2008/6/25 julien CLEMENT :> Well,

I see this thread has a lot of success ^^
And personnally I learn quite a lot.

My first motivation for static linking was to ease an end user task in
installing the game/software. But it’s not a reasonable ground afterwards,
because commercial games just provide DLLs/dylibs/so packed with the
application and copy them in a target directory of the system. So, if I may,
forget my question concerning static linkage.

Back to license problems if you don’t mind. Imagine tomorrow I’m very
satisfied
with a program and I want to make it a shareware. It is dynamically linked
with SDL,
and some derivates like SDL_image, SDL_net, and SDL_mixer.
I want to make this game paying.

What are the possible problems I may encounter:
When the game is open-source
When the game is *not* open-source
Many thanks

Julien

----- Message d’origine ----
De : Hajd? Zolt?n
? : A list for developers using the SDL library. (includes SDL-announce)

Envoy? le : Mercredi, 25 Juin 2008, 11h15mn 50s
Objet : Re: [SDL] Static link

Hello,

It is not the time overhead, but the storage space: even for really
tiny applications, you have to include megabytes of dlls when using
images, audio, etc.

Z.

On Jun 24, 2008, at 8:57 PM, Edward Cullen wrote:

In other words; don’t link statically unless you’re on an embedded
platform that either doesn’t support dynamic linking or you need
to save the overhead of dynamic linking (which ONLY applies to
embedded platforms).

Envoy? avec Yahoo! Mail.
Une boite mail plus intelligente.

SDL mailing list
SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

Edward_Cullen · June 26, 2008, 9:32pm

The intent of the LGPL, is to allow someone to provide a useful library
that can be used by an applications, without restricting the terms such
an application can be distributed under. This contrasts with the GPL,
which DOES restrict the terms of distribution.

This freedom, under the LGPL is dependent on the application NOT being a
derived work.

Whether something is a derived (as opposed to a dependent) work or not
is tricky.

Because when you use dynamic linking, it is possible to replace the
library implementation with a compatible one, it is arguable that the
application is not a derived work. This is the fundamental implication
of free use of LGPL libraries.

Static linking is trickier. As someone else pointed out, one could
distribute an object file that the user could link against a different
library on their machine (even automatically as part of the installation
process). Because the actual linking could be done against a compatible
implementation of the library, it could be argued that it is not a
derived work.

If you distribute a statically linked executable, that cannot be
re-linked, for example, as part of an embedded platform, then it could
be argued that, because the software is fundamentally dependant on the
library linked into it, then it is commonly regarded as a derived work.

What does this mean to you and me?

Using Dynamic Linking

You can licence your application however you want and you can sell or
give it away as you see fit.

Releasing an Application as LGPL or GPL.

Because you’re releasing your application under the same licence as the
library, you can link however you like.

Using static linking on an embedded platform

Choose one of the following:

a. Buy a licence and then you can distributed your application without
restriction.

b. Release your code as GPL/LGPL.

c. Become a lawyer grin

Distributing using static linking on a platform that supports dynamic
linking.

Don’t! You lose more than you gain. The cost of dynamic linking is
REALLY small and is almost always paid for during start-up (your program
will take longer to start, but will normally perform the same when
running). Dynamic linking allows the library to be
changed/replaced/updated independently of your program. This is almost
ALWAYS a Good Thing. I could give a whole treatise on the pros and cons,
but there’s plenty on the Web for you to find using your generic search
engine platform.

I think that covers most of the common scenarios you’ll come across…
as always, comments and corrections welcome

Eddy

julien CLEMENT wrote:> Well,

I see this thread has a lot of success ^^
And personnally I learn quite a lot.

My first motivation for static linking was to ease an end user task in
installing the game/software. But it’s not a reasonable ground afterwards,
because commercial games just provide DLLs/dylibs/so packed with the
application and copy them in a target directory of the system. So, if I may,
forget my question concerning static linkage.

Back to license problems if you don’t mind. Imagine tomorrow I’m very
satisfied
with a program and I want to make it a shareware. It is dynamically
linked with SDL,
and some derivates like SDL_image, SDL_net, and SDL_mixer.
I want to make this game paying.

What are the possible problems I may encounter:
When the game is open-source
When the game is *not* open-source
Many thanks

Julien

----- Message d’origine ----
De : Hajd? Zolt?n
? : A list for developers using the SDL library. (includes SDL-announce)

Envoy? le : Mercredi, 25 Juin 2008, 11h15mn 50s
Objet : Re: [SDL] Static link

Hello,

It is not the time overhead, but the storage space: even for really
tiny applications, you have to include megabytes of dlls when using
images, audio, etc.

Z.

On Jun 24, 2008, at 8:57 PM, Edward Cullen wrote:

In other words; don’t link statically unless you’re on an embedded
platform that either doesn’t support dynamic linking or you need
to save the overhead of dynamic linking (which ONLY applies to
embedded platforms).

Envoy? avec Yahoo! Mail
http://us.rd.yahoo.com/mailuk/taglines/isp/control/*http://us.rd.yahoo.com/evt=52423/*http://fr.docs.yahoo.com/mail/overview/index.html.
Une boite mail plus intelligente.

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SDL at lists.libsdl.org
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org