Featured Post


 These days, I mostly post my tech musings on Linkedin.  https://www.linkedin.com/in/seanmcgrath/

Friday, January 24, 2003

We won!

A wee Propylon specific entry this am. Propylon's Mission Control won the Professional Innovation award at the Digital Media Awards last night. Mission Control is a pervasive application server, built from the ground up on XML technologies - long before it was trendy to do so. It is also deeply, rather than superficially based on semantic xml representations of data assets and on-the-fly XML transformations. Its gratifying to get the award but I think I'm proudest of the fact that the technology has proven itself in mission critical, carrier grade deployments such as o2..

More material on XFML

XFML article on xml.com is worth a read.

Thursday, January 23, 2003

The data *is* the interface

I have a lot I want to write beneath this title but I have not got it down yet. An executive summary would be something like:

  • Systems are about how data changes state w.r.t. time (thank you Michael Jackson of AT&T for that one). To model systems, model how data changes state w.r.t. time.
  • Web Services are points in an information space that you can send/recieve data from.
  • All else - and I do mean *all* else - is simply transformation - XML to XML transformation to be precise. Every else is detail:-)

Web Services (of the doc/literal kind) serve as a standardised, simple two pin interface to processing nodes. Data does in, data comes out. (Repeat after Homer "Data goes in. Data comes out. Data goes in. Data comes out.) Thats it. No 6 page IDL. No frenetic RPC. Just data - pure as the driven snow.
Heres a phrase from a piece by Sam Ruby that I like:

"In terms of a tangible recommendation, when designing an interface I recommend starting from a description of the data that you wish to exchange. Represent it as simply as possible as name/value pairs, using nesting when structure is important. When appropriate, wrap the results in an envelope and annotate it with routing and/or security information as a header. It generally is also helpful to capture the description of these messages in both a human and machine readable terms in WSDL to aid in the development of receptors for your data. "

Yup. Yup. More to say (ansynchronous messaging, end-to-end principle, interventionist routing) but yup, yup.

XML - an overnight success after 15 years

A short article in which I worry about the overselling of XML as a panacea for all ills. Written two years ago. Things are a lot worse now :-/

No sign of 'googlechopped' being googlechopped

One hit as of today. Oh, well.

Conversational Terrorism

[via www.technorati.com], a very useful list of techniques. (To recognise of course, never to use :-).

Python design goals

[via the daily Python URL]. An interesting interview with Guido van Rossum about the design goals of Python (and by implication, the design reflected in the most excellent

Wednesday, January 22, 2003

XML lightbulb jokes

There are not half enough XML lightbulb jokes out there. Come on guys! Here is my contribution from July 2001.

Nobody expects the spontaneous glossary lookup

A nice glossary accessible via a bookmarklet from looselycoupled. Jon Udell has kickstarted
what I suspect will be a raft of cool lookup functions like this with his LibraryLookup project. As is typical of Jon he didn't just get something interesting working, he then analysed why it works and looked for the deeper insights lying beneath the surface of such things. In a nutshell, (a) URLs are the really cool thing about the Web and (b) HTTP GET can be effectively and oh-so-simply used to create Web Services.

Tuesday, January 21, 2003

Monday, January 20, 2003

MSV - a beautiful piece of work

Sun's MSV (Multi Schema Validator) is a really excellent piece of work. Hats off to Kohsuke Kawaguchi. For those transitioning from DTD to Relax or (horrors) DTD to XSD, it provides a very simple way to pick and choose schema language to validate an instance against. Note to DTD fans - it allows you to specify the DTD on the command-line instead of through a DOCTYPE declaration. This is A GOOD THING.

Sunday, January 19, 2003

The OpenOffice file format is XML you know

A number of people I know have been suprised to discover that all OpenOffice files are stored in XML. Okay, they look like binary goo at first blush but thats because they are Zipped. This article from Uche introduces OpenOffice Files and is worth a read.