Subject: Re: Semantic GNOME Desktop
From: Anders Feder <anders@feder.dk>
To: Sebastian =?ISO-8859-1?Q?Tr=FCg?= <strueg at mandriva dot com>
In-Reply-To: <200805231641.44138.strueg at mandriva dot com>
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         <200805231641.44138.strueg at mandriva dot com>
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Date: Fri, 23 May 2008 19:57:52 +0200
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Hello Sebastian,

Thanks for your reply. I've posted an excerpt of your mail on the wiki
page.

What are your thoughts on ontology alignment/matching? Is there a place
for this in your architecture? For instance, an application querying for
FOAF data should not be excluded from equivalent data stored in NCO, in
my opinion; the architecture could handle the alignment process
centrally and transparently, possibly via special plugins for the
purpose, rather than requiring each and every backend to implement an
alignment strategy of its own.

Is it possible for applications to 'subscribe' for updates to virtual
folders (or queries, otherwise) in your architecture? I see signals for
'statementsAdded' and 'statementsRemoved', at least?

I agree that stuff like contacts should ideally be stored only once;
some redundancy, on the other hand, is often useful in practice. For
instance, you will want a copy of your contacts on your PC as well as on
your PDA, so you can access your contacts even when away from the PC.

Redundancy inevitably leads to syncronization issues; a challenging,
but, I think, unavoidable subject on the semantic desktop. I don't know
if there is any solutions particular suited for syncronization of
semantic data? Perhaps one could be developed under NEPOMUK?

Best regards,
Anders Feder


Sebastian Trüg wrote:
> On Thursday 22 May 2008 15:40:59 you wrote:
> > I'm looking informally at possibilities for integrating the Semantic Web
> > and the GNOME desktop. So far, I've outlined a few ideas at:
> > http://live.gnome.org/SemanticDesktop
> >
> > I would like to ask you if you have any comments on these ideas and how
> > to proceed - and if you see any potential for collaboration with your
> > projects?
> 
> Hello Andres,
> 
> thanks a lot for your email. I think it would be a great idea to cooperate on 
> the semantic desktop front. Areas I think we can share are:
> 
> - The DBus interface for the semantic data storage. At the moment it is based 
> on Soprano [1] which comes with a full-featured RDF DBus API [2]
> - The ontologies: here we already use Xesam [3] for everything file-metadata 
> specific and the Nepomuk ontologies [4] for other stuff. This also means that 
> we do not use OWL as it was considered way to heavy for desktop use. Thus, 
> please consider using NRL [5] in combination with NAO [6] instead.
> - We are currently working on virtual folders which is pretty much what you 
> outline, too: a "view" on a sparql query (or a more generic desktop query in 
> my case). Here it would be nice to share the interface, so that KDE and Gnome 
> apps could use the same folders.
> 
> As for your backends: this is what we do, too. For example: 
> - Strigi analyses local files and stores the data (for desktop search)
> - An Akonadi agent collects information about contacts and emails and stores 
> it (actually my vision would be to store stuff like contacts only once, in 
> the rdf store)
> 
> Additionally applications can insert new information. There is not much there 
> yet except for tags and ratings and source URLs for downloaded files.
> 
> Ok, this just to get the communication started. :)
> 
> Cheers,
> Sebastian
> 
> [1] http://soprano.sf.net
> [2] 
> http://api.kde.org/kdesupport-api/kdesupport-apidocs/soprano/html/soprano_server_dbus.html
> [3] http://xesam.org/main/XesamOntology
> [4] http://www.semanticdesktop.org/ontologies/
> [5] http://www.semanticdesktop.org/ontologies/nrl/ (important part is that 
> about the named graphs, views are not implemented anywhere yet)
> [6] http://www.semanticdesktop.org/ontologies/nao/
>