8 replies to this topic

[bbqroast]

Hello,
I use SDL which (I believe) is released under the GNU license. SDL is a library, it is packaged with my program in a archive. It consists of some DLL files. I have also of course added the instructions to have it used in my program to my program.

My question is, can I legally sell my game and release it under a license other than GNU?? Would I have to package SDL separately or what. Just for those of you who are wondering to make the game work I package the SDL DLL with it (and include a line in my program to include it).

[WingedPanther73]

SDL is released under the LGPL. As long as you only link to it (using .dll files), you're fine. Also, GPL doesn't stop you from charging for software, it just requires you to provide your source code along with it. LGPL just requires you to provide the source for SDL.

[bbqroast]

I assume the DLLs are compiled so would linking to the SDL site be enough??

[WingedPanther73]

I'd have to double-check the verbiage of the LGPL as to whether a link to their site is enough.

[bbqroast]

Thanks, legal documents make my head hurt.
Wouldn't it be so much easier if:

You can copy this program, but keep the source open.

was sufficient. Besides this way normally results in hard working people getting ripped off by well richer people- But that's another rant for another post.

[WingedPanther73]

Lawyers don't write simple laws, yet we keep sending lawyers to write laws.

Try reading the US export laws on cryptography and determining whether they apply to a SHA-1 hash of a password.

See item 6 here: The GNU General Public License v3.0 - GNU Project - Free Software Foundation (FSF) The LGPL is just a less-restrictive version of the GPL, so you have to read both to understand LGPL. Basically, you have to give them the ability to get the source to the LGPL'd code. If you just have a link to the zip file of it, that would probably work, but I think YOU have to offer it.

[bbqroast]

SDL isn't Getty images so I think I'll be fine as long as I link to it. If they email me I will just upload the source to my server.

I did read somewhere when distributing GPL programs, by hand for example you could just give your customers a address of FTP server.

[Alexander]

To put it in simple terms, you can either

Freely distribute the library under a secondary download, i.e. on your site or in an autodownload during install (clearly not derivative of the library), or,

Provide, or make available (i.e. text with ftp location) your exact library version, how to download, and how to configure it to be used with your application so that the end user may compile their own or improve the existing LGPL library on their own terms without trouble from you.

Also, you may be interested that there are plans to release SDL 1.3 under the zlib license of which you may better enjoy.

[bbqroast]

Cool thanks tons
I'll just upload the source, hoping my server doesn't become a mirror!
EDIT: Wow, the zlib license looks awesome, I might even look into using it for my own code.