[josm-dev] License clarification for JOSM plugins

[Gervase Markham]

Frederik Ramm wrote:
>> Putting "GPLv2 or later" headers on all the files would not require  
>> seeking the permission of anyone. No file has been restricted to "GPLv2  
>> only" by a header, and the GPL says that if no version number is  
>> specified, then any can be used. Adding headers like that would make  
>> things much more clear.
> 
> ... if you say that the GPL clearly states "any can be used" for this
> case, then do we need to make an effort to explicitly state the obvious?

Because while the legal situation is, in fact, clear, it's not obvious 
to someone just coming along. As has been demonstrated very recently :-)

> If I had to touch every single source file I'd probably opt for
> removing the license comments there and put then in one central place.

But the _point_ of the license comments is that they are attached to 
every file, thereby making it clear what the terms for that file are. 
You need to put _something_ on each file.

As I mentioned earlier, the FSF has a "How to apply these terms to your 
new program" best practice guide for the GPL.
http://www.gnu.org/licenses/old-licenses/gpl-2.0.html#SEC4
It says:

"To do so, attach the following notices to the program. It is safest to 
attach them to the start of each source file to most effectively convey 
the exclusion of warranty; and each file should have at least the 
"copyright" line and a pointer to where the full notice is found."

Gerv