[Qt-interest] Qt 4.5 Open Source (Windows) -- is it legal to redistribute the Qt DLLs?

[Kermit Mei]

On Fri, 2009-03-20 at 16:35 -0300, Wagner Sales wrote:
> Hi Ed,
> 
> No. A basic rule for GPL/LGPL are the output of the GPL/LGPL program
> don't needs to be open. For example, if you compile with gcc, your
> program don't need be under the same license. This rule aplies for
> IDEs too, then if you write a program using KDevelop, vi, QtCreator
> and other open editors, you don't need to redistribute your code. 
> Another basic rule if you are using a LGPL lib: if you make changes to
> LGPL lib, you needs to distribute only the changes you made, not the
> entire program. 
> 
> Hopes that's helps,
> 
> Wagner 

Hello, Wagner,
I haven't understand some differences. 
The GPL tell us, if we use it, whether we modify the code of it, we must
distribute our program under GPL, isn't it? But LGPL allows us to use it
without open the source of ourself, if we haven't modify it's code.  

If I use the GPL program's libs, must I distribute my program under GPL?
For example, I use gcc compile a program on Linux, and use the
libpthread.so which is protected by GPLv2. Then, Am I forced to put my
source under GPLv2? I feel some conflict when non-open source run on
Linux ...

Thanks.
Kermit