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[XRI] Cooler XRI

From: John Bradley <jbradley@wingaa.com>
Date: Fri, 24 Oct 2008 07:54:21 -0400
Message-Id: <19832C82-1D32-4493-A562-B29319069D00@wingaa.com>
To: www-tag@w3.org

This is a copy of the blog post referenced in my previous email.   I  
am sending it to the list for the record.

John Bradley

Cooler XRI

Not that XRI themselves are not cool in the conventional sense.  Well  
as cool as an OASIS TC can make them.

What I am refering to is a property of XRI that has been there all  
along but we are now seeing in a new light thanks to our cooperative  
efforts with the W3C TAG.

The W3C has created a document "Cool URIs for the Semantic Web" http://www.w3.org/TR/cooluris/

In yet another case of great minds thinking alike: XRIs in the form of  
HXRI meet all the qualifications of "Cool URI" if we change from a 302  
redirect to a 303 redirect.

Givein that there is no reason for us not to change the redirect type  
based on the TAGs advice , we are getting closer to a common  

We all now understand that:

	* If an "http" resource responds to a GET request with a 2xx  
response, then the resource identified by that URI is an information  
	* If an "http" resource responds to a GET request with a 303 (See  
Other) response, then the resource identified by that URI could be any  
	* If an "http" resource responds to a GET request with a 4xx (error)  
response, then the nature of the resource is unknown.
Givin this understanding the "Cool URI" document shows us how to  
construct URI for "real-world objects or things".

As it happens every XRI is also about a "thing".  We have attempted to  
come up with better language than "thing".

I quite like the description used by Stuart Williams of "Platonic  
ideal" in that when I the XRI =jbradley to refer to me I am not  
literally refering to me but to an ideal of me that can be descibed by  
meta-data in the same way that a mathmatician describes a circle via a  
Both myself and any phisical circle are crude appoximations of the  

Givin that the XRI =jbradley names the PI(Platonic ideal) me how do I  
use that as a URI?

I can use the proposed sub scheme for a http: XRI and put the relative  
XRI on a base http: URI:


Now if this URI returns a 303 and link header information about where  
to retreve meta data about =jbradley and perhaps alternate resources  
relating to =jbradley based on content negotiation it is by the W3C's  
definition  a cool URI.

The cooler part is that we now have the XRI shared semantics that can  
be applied to any XRI subsceme URI to describe =jbradley.

This is achieved through a mechanism simmilar to the one that the W3C  
recommends near the end of "Cool URI".  They cite D2R Server as an  
example of using SPARQL and 303 redirects to serve RDF documents about  
"Platonic ideals".

XRI has and is proposing to do the same thing with some diffrences:
1. Using XRDS instead of RDF documents. (Yes we may add a RDF format  
for XRI meta-data)
2. Using a global scope for XRI like ARK
3. Using a http sub scheme to define the shared semantics per David  
Booth's recomendations http://www.dbooth.org/2006/urn2http/
4. Use multiple schemes as base URI for the same XRI for shared  
semantics i.e. http: and https:

I am hoping we can now make rapid progress on resolving our  
differences with the TAG to remove there objections to XRI.

Received on Friday, 24 October 2008 12:00:35 UTC

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