Re: Xenon and Fresnel

From: Ryan Lee <>
Date: Mon, 06 Dec 2004 23:56:30 -0500

I am definitely open to further discussion on this topic, but my basic
reaction is no.

I believe any project benefits from the searchlights of multiple,
separate implementations and so I'm not opposed to the idea of an
implemention Fresnel in Xenon. I would like to see at least one
independent, lightweight implementation of Fresnel out there, and so I
don't think I can personally contribute to an effort concerning Xenon
and continue working on developing the existing Fresnel schema and a
codebase simultaneously.

Emmanuel Pietriga wrote:
> Chris Bizer wrote:
>> What do you think about Xenon?
> I like the XSLT-inspired template approach, but I think Xenon is much
> harder to learn than XSLT. One reason for this is that it is RDF-based,
> which makes its syntax and model more complex. So it seems powerful, I
> find it elegant, but I'm not sure it can reach a lot of people "as is".
> Maybe with some kind of front-end. Or higher-level specification means
> such as a fresnel implementation on top of it (as a start).

Hopefully Stefano will chime in here with some of what the SIMILE
development team discussed. For myself, I feel Xenon may be overly complex.

>> I was also talking about Fresnel with some guys who were presenting
>> semantic portals at ISWC. They had similar, less expressive and more
>> ad-hoc display languages in their portals and were very interested in
>> Fresnel. It seams like many people are seeing the need for agreeing on
>> a display language and we could get some adopters easily, if we were
>> coming up with something flexible, but easy to use ....
> That would be nice.

Not having been to ISWC, I still found semantic web developers
interested in the Fresnel work :)

>>>> As I already said at ISWC, we are using an RDFpath like selector
>>>> language, where you are using SPARQL.
>>>> ?TARGET/_at_vCard:TEL [ @rdf:type=<>]
>>>> Most of your example queries aren't to complex and don't use the
>>>> expressivity of SPARQL. So it might be an idea to switch to RDFpath in
>>>> order to achieve better readability.
> I haven't looked thoroughly at SPARQL yet, but I am really much in favor
> of a powerful-enough RDFPath language.

As am I, though I have left that issue out of the current Fresnel code.

> Chris Bizer wrote:
> Ryan: I saw in the SIMILIE repository that, you started implementing
> Fresnel ( What is the
> context of this work? What's the timeframe?

Yes, I wanted to get a sense of what code for Fresnel would feel like as
well as a working experimental demonstration of what it would do. I am
working on the most important stage in the process right now,
translating from selected content to a set of generic-enough Velocity
friendly objects. I have commented the code up to this point, so folks
can run the 'doc' ant task to see some javadoc pages. The timeframe is
ASAP; Fresnel code is often at the top of or near the top of my stack
right now. We have an interest in seeing context switching within
Longwell, and we'd rather stop hacking on our Longwell display ontology
and use a Fresnel implementation instead.

Ryan Lee       
W3C Research Engineer    +1.617.253.5327
Received on Tue Dec 07 2004 - 04:56:38 EST

This archive was generated by hypermail 2.3.0 : Thu Aug 09 2012 - 16:39:17 EDT