installation requirements for ridesf

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Dec 10, 2009, 11:01:41 PM12/10/09
to sf-bike-planner
FYI, here's all the stuff I had to install so far. Might be missing
some as I have not actually run anything yet.

1. Install PostgreSQL

2. Install qGIS

3. Install GEOS/PROJ frameworks (not necessary if you use the
standalone installer for qGIS)

4. Install PostGIS

5. Install pgRouting

pgRouting is GPL, which I believe requires us to release all our
source under the same license.

Matthew Heberger

Dec 11, 2009, 11:51:47 AM12/11/09
Amar and John, looks like you've been busy...

"pgRouting is GPL, which I believe requires us to release all our source under the same license"

That's an interesting idea. If you use a snippet of GPL-licensed code in your project, then you are required to make everything else in your project conform to the same license? Based on about 5 minutes of research, I think that is the case:

If I add a module to a GPL-covered program, do I have to use the GPL as the license for my module?

The GPL says that the whole combined program has to be released under the GPL. So your module has to be available for use under the GPL.

But you can give additional permission for the use of your code. You can, if you wish, release your program under a license which is more lax than the GPL but compatible with the GPL. The license list page gives a partial list of GPL-compatible licenses.

I found the discussion quite confusing. Apparently, you can have a GPL licensed project, but you can still own its copyright and charge money for it. Anyhow, I don't want to put the cart before the horse and get too bogged down in details with this.

Incidentally, I recall that ridethecity uses pgRouting, but there's no mention anywhere on their site of a license or a user agreement.



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John Roark

Dec 11, 2009, 1:49:15 PM12/11/09
My understanding of this issue is as follows. The only code we would
have to release under the GPL is code that directly links with or
modifies GPL code that we plan on distributing. So, for example, if I
modify the astar algorithm from pgRouting and distribute the changes I
would have to license the changes under the GPL. If I make changes to
the astar algorithm from pgRouting but don't distribute it (only use
it on my server) then I don't have to license anything under the GPL
because I'm not distributing it. Code that links to shared libraries
that are GPL does not necessarily need to be GPL'd. None of my code
that I have released needs to be under the GPL, because I am only
using the public API's and not even directly linking with pgRouting,
Postgresql is BSD, shapelib is MIT, and libCGI is GPL v2.1 (I am
dynamically linking with the shared library), that and until recently
I wasn't distributing it at all.


Matthew Heberger

Dec 11, 2009, 1:59:52 PM12/11/09
Thanks for the clarification! This stuff is all pretty new to me.

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