Re: ddraw.h, dinput.h and dsound.h in Cygwin/MinGW

I have just reviewed the three files in question. You definitely do not need 
them to be relicensed to use them in another project. The LGPL on the files 
will not affect executables generated using them.

An executable using the files would only be subject to the LGPL if the 
executable included a *substantial part* of the *expression* of concepts in 
the header files in question. The use of *facts* from those files is not in 
itself sufficient to cause the executable to be affected by the LGPL.

An executable may use some of the facts, but none of the expression will make 
its way into the executable from these particular files.

Even if expression were incorporated into the executable, most of the 
expression is dictated by the interface that the files are facilitating, and 
thus would not be protected due to lack of sufficient creative elements. 
Unless you are literally copying significant sections of the file, the LGPL 
simply doesn't apply because you would not be undertaking an act that would 
be contrary to the copyright.

So, the effect of the LGPL in the case of these three headers is only on 
copying the text of the file - it does not affect executables at all unless 
they incorporate the text of the file or a precompiled version of the entire 
file.

The libstdc++ headers are a different case because the use of inline methods 
means they do contain protected expression in parts that would be copied into 
the executable. Thus the specific exemption is necessary there.