Remembering SkiCal

Graham Klyne wrote: I'd completely overlooked SKICal work...

Dear Graham, Libby and friends,

Sorry, we are working on getting www.skical.org back up. I afraid we 
missed a renewal:-(

Here is some more information that might also have been forgotten, 
perhaps expeditiously so – who knows?

SkiCal was an attempt to create a schema extending RFC2445 to cover all 
possible public “resources”. Resources in this case meaning just about 
anything a human or organization could interact with! (timidity was not 
our hallmark).

In order to interact you might want to know what was offered – by who, 
when, where etc... And you might want to know just what sort of 
technicalities or requirements were involved in such an interaction. And 
you might just be able to sync this information with your own calendar.

A souped up yellow pages, as someone called it.

We were counting quite heavily on the centralist nature of Sweden, (SKI 
is an acronym for “/Svenska kalendarium initiativet/”) to establish 
standard usage of our schema. That is, we thought we could convince 
government to stipulate the use of SkiCal for the entire flora of its 
resources, and the resources it subsidized (which are considerable), in 
order to save money and better the lot of our citizenry - or at least 
get them to the cinema on time.

Since commercial operations, such as CitySearch, then as now preferred 
to regard their listings of some one else's public events as their own 
private property, we figured that the only way to get them to go along, 
was through government fiat. Our primary target for SkiCal 
implementation was publicly funded national and local tourist boards. 
With enough SkiCal out there, others would be forced to follow suit, or 
so we reasoned.

Our first IETF draft entailed moderate extensions to RFC2445. We were 
inspired by the fact that browsers at that time (1999) could rather 
effortlessly download vCard and vCal/iCal objects and insert them into 
savvy scheduling applications.

As we continued to update our drafts, spurred on by IETF's 6 month 
expiry limits, we merrily added more and more “features”, despite the 
fact that adoption of our first schema was moving on very slowly (albeit 
not insignificantly).

The first draft from 1999 can be found here:

http://www.watersprings.org/pub/id/draft-many-ical-ski-01.txt

It was promoted by the Swedish National tourist board and the tourist 
councils of the larger cities here.

I wrote a paper for XML 2001 in Orlando...

http://www.idealliance.org/papers/xml2001/papers/html/05-04-06.html#d28e45745 


...an absurdly ambitious effort to explicate the state-of-the-art of the 
date-time aspects of “the souped up yellow pages”. As a whole it is most 
likely unreadable, but some of the problems with iCal/ISO8601/XML 
Schemas I covered therein are, as far as I know, still relevant today:

Ambiguities caused by start/end inclusive – exclusive date-time formats.

Inconsistencies in calendar-explicit – period-explicit durations

Representation problems with “midnight crossings” (when Cinderella turns 
into a pumpkin)

The only comment I ever heard on the Orlando paper was from my 
volleyball buddy DanC, via DanBri, who said I was refining the art of 
micro-parsing – I don't think it was meant as a compliment:-).

I also wrote a paper for WWW2002 in Honolulu on directories, where 
SkiCal was exemplified. In this paper I gave some of the arguments 
against universal (unified schema) directories.

http://www2002.org/globaltrack.html

The “current” SkiCal draft #6 was written in 2002. It has a self 
standing “Opening Times” schema written in XML. Since SkiCal #06 is 
itself in mime-directory format, I included the opening times 
declaration as encapsulated XML.

http://www.watersprings.org/pub/id/draft-many-ical-ski-06.txt

That's it.

Nice weather we're having,

Greg

Received on Sunday, 9 May 2004 08:24:19 UTC