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I’ve set up TrackBoot, a place for trackbacking around the upcoming Reboot. Start sending your trackback pings!

Thomas Madsen-Mygdal has invited me to join Reboot 6, which takes place here in Copenhagen on 20 June. I want to will participate, and will try and clear the whole day and take part in the full programme. It’s an impressive programme: First, eight great speakers: Tim O’Reilly, Dan Gillmor, Marc Canter, Meg Hourihan, Cory Doctorow, Jason Fried, Scott Heiferman, and Ben Hammersley, and then an Open Space evening. And I can walk there.

I missed last week’s W3C Working Draft on Web Services Architecture (WSA), but am happy I finally found it. René is not going to like this 🙂

There’s an interesting definition of web services:

Definition: A Web service is a software system identified by a URI, whose public interfaces and bindings are defined and described using XML. Its definition can be discovered by other software systems. These systems may then interact with the Web service in a manner prescribed by its definition, using XML based messages conveyed by internet protocols.

I can live with this. And I think René can too. I think it’s more or less “compatible” with the way we talk about services in our white paper. Now, René, the good stuff comes when W3C talks about architectural styles:

We can identify two major classes of “Web services”: REST-compliant or “direct resource manipulation” services in which in which the primary purpose of the service is to manipulate XML representations of Web resources using the a minimal, uniform set of operations operations, and “distributed object” or “Web-mediated operation” services in which the primary purpose of the service is to perform an arbitrarily complex set of operations on resources that may not be “on the Web”, and the XML messages contain the data needed to invoke those operations. In other words, “direct” services are implemented by web servers that manipulate data directly, and “mediated” services are external code resources that are invoked via messages to web servers.

This makes a lot of sense to me (so much that I get a feeling I actually don’t get it at all …). Basically, I am putting W3C back on top of my list of standards/reference bodies relevant to service-oriented architecture. The WSA would be a good candidate for governments to adopt in our interoperability frameworks. It needs consolidation, of course. I notice Microsoft is absent, so it’s going to be interesting to see how it goes.

My impression is that Microsoft goes 100% for OASIS and for WS-I Basic Profile – Version 1.0 Board Approval Draft (BdAD) from 2003/03/28. The WS-I Basic Profile 1.0 consists of a set of non-proprietary Web services specifications, along with clarifications and amendments to those specifications which promote interoperability.

WSA, WS-I, WS-*, what’s the clue in all of this?
Architectural styles can be expressed in many ways. One main style we all seem to agree upon is a service-oriented architecture (SOA). W3C says that WSA is an instance of a SOA. An SOA is a specific type of distributed system in which the agents are “services”. The WS-I Basic Profile then would be an instance of WSA, but, being a Profile, might invoke some boundary issues, as we saw with RSS last week. Or is that a wrong picture?

These are busy days in the RSS community. Dave Winer thinks Microsoft is “going to fuck all of us” and steal RSS, and suggests:

We could establish a profile of RSS 2.0 and implement strict compliance with that profile in the major blogging tools. We could give that profile a name, and jointly market it to users.

Sam Ruby said “Excellent!”, and so did many others. Don Box made a proposal, for which Sam Ruby hosts a disussion thread. Mark Nottingham announced a new RSS wiki which would feed in to the RFC as well as the Profile as they evolve. Jørgen Thelin will work on the XML schema for the Profile. Timothy Appnel asks the basic question:

At what point does the specification stop and extensible modules begin?

Tim Bray jumps in and uses the S-word, “Standardization”, and says:

Standards happen when someone is willing to get behind them and burn the cycles and the brain cells and not stop till it’s done. If someone’s willing to find the time, it can be done, otherwise not.

Tim goes through the various potential standardisation bodies, and ends up picking IETF, and supports the RFCifying of RSS 2.0 that Mark Nottingham started a few weeks ago. Don Box suggests the standardisation process is taken to OASIS instead, but doesn’t seem to have any hard opinions on this.

Many in the debate seem to take for granted that RSS 2.0 has won. This is a foregone conclusion, and is challenged by many, for example,
Ben Trott and Danny Ayers, who sticks with RDF-based RSS 1.0. Maybe they should forth and suggest standardisation through W3C (who uses RSS 1.0).

But wait, in comes a new specification that is intended to act as a bridge between RSS 2.0 and RSS 1.0 on a technical level. Simple Semantic Resolution (SSR) Module for the RSS 2.0 syndication format. The purpose of SSR is to provide a mechanism by which the semantics of an RSS 2.0 document can be unambiguously resolved to an RDF model. Will this really work? It would be great if it would.

In terms of the standardisation process, the idea of using a Profile is an intersting trick, and probably the right way to take with RSS. Profiles are suitable for emerging technologies, and RSS is still an emerging technology.

As I understand the profile concept it is more or less like American English and British English, which could be seen as two profiles of the same language. It’s a mess having two ways of spelling the S-word, standardisation and standardization, but somehow it works, probably due to the two profiles being used literally by millions every day. And, if anyone should ever dream of standardis/zing English, they’d better get up early, because that’s going to be a long ride.

One of my work projects is about creating what we call a Reference Profile for eGov Interoperability. This is basically the Danish pendent to UK’s e-GIF, Germany’s SAGA, i.e., a national Interoperability Framework. The Reference Profile will contain technical policies and specifications which are formally recognised by the Danish government.

I’m happy we chose to call our framework a profile, although the Reference Profile is much more “meta” than, say, the Basic Profile Version 1.0 (Board Approval Draft, BdAD). In fact, our Reference Profile could end up refering to the Basic Profile.

It is worth noting that it was only this week W3C released SOAP as a Proposed Recommendation (that’s one step closer to becoming a W3C Recommendation, but we’re not quite there yet).

The Danish XML Committee is working on an Integration Handbook featuring (Part 2) guidelines for how to use web services in integration projects. A draft is available for pre-consultative comments (you can send comments to me).