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From Paolo Castagna <>
Subject Re: Interest in JENA/RDF (was RE: Versioned/Historical Documentation ...)
Date Wed, 23 Nov 2011 07:52:49 GMT
Hi Dennis

Dennis E. Hamilton wrote:
> Paolo,
> I took your advice and also obtained "Programming the Semantic Web."  It arrived yesterday.
> On first glance, that looks like a nice, easy introduction in part I. Semantic 
> Data.  Not sure what I'll find when I get into chapter 2. Expressing Meaning, 
> but it should be interesting and it appears well-written.

Good to hear that.

If you are not a programmer (apologies if you are) there are some chapters you
might find it "boring" or not useful, however reading them quickly is useful in
understanding how things works (can work).

The authors have a very pragmatic and practical view (which IMHO is great),
probably driven by the fact that they all worked at Metaweb (acquired by Google)
on Freebase ( a great and real world example on how
communities can grow and nurture structured data (... if only this could happen
in a distributed way, across the Web and not within a single data silo...)

Once you finish "Programming the Semantic Web" and you move into "Semantic Web
for the Working Ontologist" I would be curious to hear your opinion on the two
different books (and the two point of views of the world of "Semantic Web"). :-)


>  - Dennis
> -----Original Message-----
> From: Paolo Castagna [] 
> Sent: Friday, November 11, 2011 09:22
> To:
> Subject: Re: Interest in JENA/RDF (was RE: Versioned/Historical Documentation ...)
> Hi,
> thanks for all these info, helpful and interesting. A few more comments inline.
> Dennis E. Hamilton wrote:
>> I am on the PPMC of the Apache project.  I also pay attention to the
ODF Toolkit project.
>> My interest in Jena is generic, as is that of some colleagues who are interested
in semantic markup notions.  And I am a neophyte around RDF.  The books I have read so far
(one for a course) I found to be junk with regard to how RDF was handled and worse with respect
to the semantic web.  I have some that I have not read (including Shelly Powers' book) that
it would be good to attempt.  I do need to finally cough up a few bucks and get a copy of
"Semantic Web for the Working Ontologist", recommended to me by other inquisitive folk.
> One good book is "Programming the Semantic Web":
> I really recommend it to you, before the
> "Semantic Web for the Working Ontologist".
> If you have time for just one, I suggest you pick the first one.
> My humble opinion.
>> Also, I am on the OASIS Open Document Format (ODF) Technical Committee.
>> As you have noticed already, the ODF Toolkit project is working toward implementing
the RDF support that there is in ODF.  Some ODF processors are incorporating support for RDF
in various ways.  It has been demonstrated in mobile implementations of ODF viewers.
>> ODF has a compound package structure based on the use of Zip as a container.  (There
is also a single XML file mapping of the format, but most of the RDF provisions are incompatible
with that case.)
>> RDF shows up in the ODF 1.2 format in four ways:
>>  1. The package specification (part 3) includes provisions for RDF files being incorporated
in a package.  There is also a specific package file, a manifest.rdf file that has some vaguely-defined
usage.  It is always RDF/XML.  There is an OWL ontology that can be used in that file (or
anywhere, for that matter).  It is described as providing a manifest of other RDF files in
the package, but that may not be exactly right.  It appears to be a manifest of where there
is RDF in other files (not necessarily RDF files) in the package.  Maybe both.  I must figure
that out some day.
>>  2. The main document specification (part 1) adds an additional OWL definition that
can be used to have more-refined material in RDF that have subjects and resources in the XML
files that are part of the ODF document.
>>  3. RDFa notions have been adapted for use within the XML element that carries the
main content for an ODF document.  These usages are governed by the RNG grammar and they may
be incomplete.  (Why RDFa when the content element is XML and <rdf:RDF> is embeddable
as an extension anyhow is a legitimate question for which I have no answer whatsoever.)
> In relation to RDFa see also:
> (by Damian, Apache Jena committer and PPMC 
> member). :-)
>>  4. There is a presumed use of GRDDL (a single attribute in the root-element XML
tag of the ODF document) for somehow extracting all of the RDF and non-RDF metadata embedded
in the content material.
>> I shall refrain from expressing a strong opinion about this, but if you were to suggest
it is not good work, I would not flinch.
> In my humble opinion RDFa as superseded the need for GRDDL.
> I could be wrong on this and this is just my personal opinion.
> Microdata vs. RDFa is a big/long debate to follow.
> One requires/demand more governance than the other, thinking about that in 
> relation to Microdata and RDFa is IMHO an interesting (non technical) perspective.
>> So another reason for my interest in Jena is to find specimens of good work and a
basis for good tools that make sense out of whatever it is that has been enabled by the ODF
specification having a check-mark in the RDF-supported? box.
> Very interesting... in particular in the context of Apache Software Foundation.
> Thanks for sharing all this with us.
> Paolo
>> Finally, I am unaware of any way that an ODF 1.2 document containing RDF can be converted
to a Microsoft Office document and somehow carry the RDF over.  Furthermore, I would be absolutely
amazed were Microsoft's own support for the ODF format to do anything but ignore all RDF material
in an ODF document and ever preserve/produce any of it.  I find that inconceivable based on
how difficult it would be to make an interoperable implementation based on what there is in
the ODF 1.2 specification.  Another reason to understand Jena, I think.
>>  - Dennis
>> -----Original Message-----
>> From: Paolo Castagna [] 
>> Sent: Friday, November 11, 2011 06:37
>> To:
>> Subject: Re: Versioned/Historical Documentation (was RE: How to decide to release
>> [ ... ]
>> My curiosity, are you using Apache Jena and/or planning to use it in the near
>> future?
>> Are you involved in OpenOffice and/or the Apache ODF Toolkit?
>> Do you know if there is anything interesting going on there in relation to
>> RDF we should be aware of?
>> Looking at Apache ODF Toolkit and how it relates to RDF (and Apache Jena) and/or
>> Apache Tika and/or Apache Any23 and/or Apache Nutch is on my (too long) todo
>> list.
>> Paolo
>>   [1]
>> [ .. ]

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