[Proj] libproj4 license and related hassles

Gerald I. Evenden geraldi.evenden at gmail.com
Thu Nov 13 13:16:15 EST 2008

When I first changed over to the libproj4 system it was recommend by I forget 
whom that a license be put on the software.  Following this recommendation I 
chose the most liberal license I could find which was the the so-called MIT 
or X11 license plus a copyright statement.  The later to mainly protect 
against someone else trying to copyright the material and potentially 
removing it from the public domain.

Everything went fine and nobody complained until I used the GNU library GSL 
and a seemingly disasterous situation occured: the GPL.  I pointed out that 
GSL usage was only for one rarely used projection and the GSL linkage to the 
library could easily be edited out with switches in the Makefile.

Again, cries of dismay occured when I used the GSL in solving the inverse 
projection problem.  Again, my usage of the library was based upon using 
better material than I could code up without a great deal of effort and time.  
Why reinvent the wheel?  And, again switches were installed to allow easy 
elimination of having to use GSL and suffer the horrible restrictions of GPL.  
But in this case, such action causes losses that are a bit more significant 
than that of not using a rare projection.

The GPL dilemma will arise again as I embark on building a better proj/lproj 
mouse trap but in this case software requiring GPL licensed material is a 
critical element of the program and cannot be simply edited out.

My last comment relates to my pausing on the Wikipedia page related to the MIT 
license ( http://en.wikipedia.org/wiki/MIT_license ) and the comment in the 
second paragraph stating thst the MIT license is "GPL-compatible."  Not being 
a lawyer I am note sure that I understand all of the ramification but I am 
going to stop worrying about future encounters with GPL and consider any 
problems between libproj4 and GPL non-existant.

The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist

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