[Freegis-list] ERMapper ECW License problematic

[Raphael Jacquot]

Tom Lynch wrote:
> Just to clarify, the Public Use License Agreement for ER Mapper's ECW 
> and JPEG 2000 codecs and the related SDK is not the same as the GPL.  
> It's described as "GPL-style" to make it clear to potential licensees 
> that it carries a copyleft restriction for anyone wanting to distribute 
> software that uses it.
>  
> It is true, and somewhat unfortunate, that it does not conform to the 
> FSF's guidelines for "free" software.  This is something that comes 
> under regular review at ER Mapper.  We could, for the most part, 
> transfer the license to a straight GPL dual license, but we are somewhat 
> concerned that the ECW format might be modified by third parties, 
> creating format compatibility problems.

you may want to consult the FSF about being the guardian of the data 
format (accepting new features along the way).
by publishing the format specification, you ensure that no undue 
modification of said format can occur without proper justification. 
anything not following the spec is NOT an ECW file.

I suppose you have a version number in that data format somewhere...