[OSGeo-Discuss] Thematic Mapping Engine as Open Source?

Christopher Schmidt crschmidt at crschmidt.net
Mon Jun 23 05:46:24 PDT 2008

On Mon, Jun 23, 2008 at 12:01:25AM +0100, Bjorn Sandvik wrote:
> My plan is to release TME as an open source project under a GNU GPL 
> license v3, and use SourceForge as a code repository.

Is there a strong reason behind these choices? These days, I probably
wouldnt' go with either of them, personally.

Looking back, I realize that the GPL license may well be related to the
fact that Ext itself is GPL licensed. I wrote the rest of this before I
thought of that, but I think it's valuable as a general statement for
users thinking of licensing Javascript libraries anyway. It might still
make sense, if the restriction is Ext based, the make it clear that your
library itself is licensed as $permissive_license, and combining it with
Ext makes it GPL licensed: This way, if someone were to buy an Ext
commercial license, they could still use it under more permissive terms. 

If you are a commercial entity looking to make money with open source,
the GPL may well be a very good choice. Essentially, you are the only
organization that can make improvements to the code that other people
can't have -- as the copyright owner, the license doesn't apply to the
work you do. (Once you have a project built with lots of poeple's
copyright, that does change, but.) However, if your goal is to create a
toolset which is widely used, and you are less concerned about
maximizing profit from your actions, it seems possible that a less
restrictive license might make sense. (An example of a successful GPL
licensed project is ExtJS itself.)

For example, one of the things that OpenLayers users have commonly
requested is the ability to do thematic styling in the way you describe
for their data: The coveted "SLD editor" is a concept that has been
tossed around, literally for years. The Ext browser work that you have
done would form a perfectly suitable base -- but OpenLayers is BSD
licensed, and extensions to it are strongly encouraged to be BSD
licensed as well, for reusability.

As a result, if the work that you are doing were to be GPL licensed,
then I would not feel comfortable encouraging a user to use your code.

Part of this problem is actually specific to browsers, imho: the use of
the GPL for Javascript software is 'somewhat weird': there are few
definitions of where the lines are drawn in Javascript. (The Linux
Kernel doesn't 'pollute' complied code that runs on that platform, but
where does the line get drawn for Javascript libraries?) I'll admit that
my dislike of GPL is strong enough that I have spent much less time
investigating it; it's possible these questions are easy to answer, but 
I don't know.

Sourceforge bothers me, to some extent, but I think this might be mostly
historical; I tend to prefer Google Code these days (though, see recent
thread about Google Code blocking exports as per US Law, which sourceforge
may not do). I don't know if there's any real reason to use one over the
other; certainly, startup cost with Google Code was low, and you even
get a built in wiki.

Christopher Schmidt
Web Developer

More information about the Discuss mailing list