I’ve been hunting decent Catalogue Service clients. I want to use one in my web applications, and if I’m going to put any work into it, I’d like to be able to reuse it as an ArcMap plugin. Now, ESRI’s got their own, closed-source Portal Toolbar. However, my initial assessment says it has no soul; it relies on ESRI’s metadata shortcut nodes. Not cool, not extensible, and not useful as a library for my web applications.
I did find a couple of FOSS CSW clients… one from Deegree (LGPL‘ed), and one from GeoNetwork Opensource (GPL‘ed). To make a long story short, the Deegree one isn’t going to work. So I’ve strapped on my scuba gear, and begun the descent into the world of the GPL.
Now, the GPL FAQ tells me that I can modify GeoNetwork’s code however I want, as long as I don’t share it. I’m assuming that means I’m allowed to modify it for my web applications. Dive much deeper than this, and the barotrauma starts to kick in. I can’t distributed code that links closed-source libraries (ArcGIS’s) with GPL’ed libraries. Okay… but where do you draw the line on what’s considered linking?
Its entirely reasonable to use GeoNetwork’s GPL’ed CSW client to call a closed-source CSW server. Can I interpret this to mean that an XML web service is enough to differentiate between the GPL’s concepts of bundled programs and combined modules? So, what, I expose my server-side, modified, GPL’ed CSW client to ArcMap via SOAP? That doesn’t exactly make me feel happy technology-wise, and violates the spirit of the GPL.
To the point, I’m hoping some OS-GIS people out there will help me do a very bad thing. I’m hoping GeoNetwork’s CSW client can swim to more pleasant LGPL waters {minus some GPL’ed dependencies}. I’ve previously made ESRI-kool-aid inspired comments that OS-GIS needs more ArcGIS plug-ins to subvert ESRI users. I’m not sure GPL’ed clients are going to get us there.
Comments? Any GeoNetwork people out there?
UPDATE:
Paul Ramsey says fear not! The GPL’s code-mixing considerations shouldn’t affect me, see the comments for details.
May 9, 2007 at 10:36 pm |
Do you distribute ArcMap? No, ESRI does that! You distribute a CSW client, which people install next to ArcMap on their own later. You’re free and clear, as long as all the code in your CSW client (the Geonetwork stuff and whatever you add) is GPL. In the same way, the (GPL) PostGIS can be used with the closed source EnterpriseDB, because they are distributed separately.