- From: Graham Klyne <GK@ninebynine.org>
- Date: Mon, 11 Oct 2004 14:58:53 +0100
- To: Danny Ayers <danny.ayers@gmail.com>, rdfweb-dev@vapours.rdfweb.org, www-rdf-interest@w3.org, semanticweb@yahoogroups.com
- Cc: rss-dev@yahoogroups.com, atom-syntax@imc.org
I think one of the key benefits of RDF is described in this blog-piece by DanBri ("missing isn't broken"): http://rdfweb.org/mt/foaflog/archives/000047.html Atom's scope isn't as broad as RDF, so maybe the full-on RDF approach is more promiscuous than necessary, but I think it's important, for example, to take two or more Atom feeds, possibly containing different and/or overlapping information, and compose them in a well-defined way into a single feed. This is what RDF can do. #g -- At 14:19 10/10/04 +0200, Danny Ayers wrote: >Issues of extensibility and language interop for the Atom Syndication >Format [1] have been bouncing around the Atom (IETF) group from day >one. Right now I think discussions may (again) be at a point where >input from the RDF/FOAF community could be helpful. > >The Atom charter [2] says: >[[ >The format must be able... >...to represent additional information in an user-extensible manner. >... >The Working Group will also take steps to ensure interoperability, by - >...describing how one migrates from the various RSS versions to the >Atom syndication feed format. >]] > ><probably-biased-background> >There are various dialects in use, but generally RSS syndication >material comes under the umbrella of either RSS 1.0 or RSS 2.0 (the >version numbers are only of political significance). > >RSS 1.0 [3] is defined as an RDF vocabulary, with a constrained subset >of RDF/XML as its exchange syntax (over HTTP), so there's clearly some >overlap with RDF efforts. RSS 1.0 extensions must follow the >constraints of RDF. So RDF is at least potentially a factor in Atom's >user-extensibility and must be a consideration when format migration >is under discussion. > >RSS 2.0 [4] is defined as a 'simple' XML format. It hasn't got a >namespace itself, though any material in other XML namespaces can >appeared in the document and be called an extension. Most syndication >tools (for publishing and reading) support both formats. Most >syndication tools only support enough of the RDF model to be able to >extract the syndication-domain data (there are notable exceptions, and >of course virtually all RDF tools can consume & process RSS 1.0 out of >the box). Developers of syndication tools tend to have expertise with >regular expressions. > >Aside from all else, there is (loosely) a polarization of opinion >among Atom WG members on how it should tackle extension and interop >issues, this being roughly parallel to that of RSS 1.0 vs. RSS 2.0. > >One pole is probably most easily expressed by saying Atom should've >been defined as an RDF/OWL vocabulary and the exchange syntax made >compatible with RDF/XML. > >The other pole is that Atom Core should be totally bolted down, and >extensions should simply be partitioned off using XML namespaces. >There would be no systematic approach to those extensions, anything >could go anywhere. > >I would guess that group consensus generally leans towards the latter >pole. (Come to think of it, probably everyone agrees with the >bolted-down core part). ></probably-biased-background> > >In [5] Robert Sayre describes an option for applying potentially >arbitrary properties to Atom entries in a uniform fashion, which may >be enough (given a bit of polish) to disambiguate extensions into >RDF-compatible statements. His suggestion hasn't brought immediate >condemnation from the core+namespace-only camp. Which is promising. > >But how workable does this seem from the RDF point of view? To me it >looks like the kind of structural constraint suggested will go a long >way towards allowing extraction of viable RDF from fairly arbitrarily >extended Atom documents e.g. using XSLT -> RDF/XML. All the usual >suspects like FOAF and DC could be used to make richer Atom documents, >without compromising the core format. Does that sound about right? Or >wouldn't it work? Or is there a better approach to RDF-compatibility >that wouldn't worry the simple-XML camp? > >Why does it matter? I think RDF potentially stands to gain quite a lot >from Atom, in the form of a relatively lightweight but versatile and >thoroughly spec'ed transport (and editing protocol) which is likely to >gain widespread deployment. Atom can gain potentially a lot from RDF, >up front for its intuitions into modelling on the Web and longer term >through compatibility with (and adoption by) RDF-based systems. Then >everyone gains when all these systems are joined together... > >Cheers, >Danny. > >[1] http://www.intertwingly.net/wiki/pie/FrontPage >[2] http://www.ietf.org/html.charters/atompub-charter.html >[3] http://purl.org/rss/1.0/spec >[4] http://blogs.law.harvard.edu/tech/rss >[5] http://www.imc.org/atom-syntax/mail-archive/msg10481.html > >-- > >http://dannyayers.com ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact
Received on Monday, 11 October 2004 15:19:22 UTC