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This argument boils up now and again, it is one of the great xml-dev permathreads (that namespace uris are a mistake) and as such should be presented to beginners in the xml world for their enlightenment. That said this article is probably not a good introduction to the matter because it seems highly inaccurate (I say seems being mindful of the fact that I myself may be mistaken on matters.)
Areas where I take exception with this article are as follows:
1. The statement "Using URIs to identify namespaces is a problematic approach with many usability flaws, all of which would be solved if namespaces were identified by the namespace prefix instead." would be far more reasonable if you identified how the prefix should then be resolved for said prefixes? Would each parser be required to have a list of known prefixes, would the meaning of prefixes be determined by querying a registry of prefixes, or would it just be a weird element name.
2. without checking I remembered the namespace for XMLSchema, at any rate that namespace uris tend to be long and cryptic should prompt the question as to whether actual http uris tend to be long and cryptic.
3. "There was an effort to develop RDDL (Resource Directory Description Language) expressly for creating documents to sit at the end of HTTP namespace URIs and direct XML tools to associated resources such as style sheets, schemas, and documentation. It is not used by any tools on the Web and with good reason: there are better ways to associate resources with individual XML documents." Although I would certainly agree that there is not much RDDL usage there is indeed some, as usual xml.coverpages has a nice listing of relevant rddl resources http://xml.coverpages.org/rddl.html some of which point to rddl sites. It should also be noted that there are RDDL modules for popular programming languages php and perl that I am aware of, and of course XSV uses RDDL to derive the location of a schema for a namespace if it does not have one to use.
4.
"Namespace URIs give people the ability to write XML documents with arbitrary prefixes like <foo:schema> or <superluminal:transform>, but people don't do that, sensibly enough, as it would be confusing and serve no purpose."
well no, but people sometimes do do <s:schema> or <x:transform> because they find that quicker than <xsd:schema> or <xsl:transform>, and generally the ones that do are the more advanced users.
5.
"RDF/XML, the XML syntax for RDF that seems to have been the driving force for the adoption of namespace URIs, does not need namespace URIs"
I don't know where you get this theory, the three guys on the xml namespaces rec. Tim Bray (Textuality) <tbray@textuality.com>
Dave Hollander (Hewlett-Packard Company) <dmh@corp.hp.com>
Andrew Layman (Microsoft) <andrewl@microsoft.com> are not widely known for their association with RDF, Tim Bray could be considered an RDF skeptic http://www.tbray.org/ongoing/When/200x/2003/05/21/RDFNet (in fact it is recent essays like this that caused me to forget he ever was associated with RDF at all), Microsoft does not seem to like RDF, so why the hell did they work on this thing if it had to do with RDF. There was no mention of RDF in the spec, in Namespaces for XML 1.1 there was no mention of RDF. Maybe it didn't mention it in the first spec because it was released a month before the RDF specs, but in the second spec? Hmm, maybe they just didn't mention it in the second spec because they don't care about RDF. Which means that probably their intentions for having namespaces are those outline in the spec, which in no way mention RDF. I am perhaps wrong about this, but given the lack of a mention for RDF in the namespaces specs I would like a reference for your claim that namespaces were made to support RDF/XML (especially given that RDF/XML was one possible serialization of RDF, and was given as an option at the time that the eventual success of XML was very much up in the air.)
6. "org.w3.xsl.transform" you can already name a namespace in this way, your article might lead the uninformed to assume that they couldn't
7. "Given that Java predated the XML Namespaces specification, one can only assume that URIs were chosen to identify namespaces for reasons other than syntactical convenience, such as their intended use in the RDF/XML syntax."
Or that URIs were already an identification scheme known to people and that held within them the possibility of using URNs http://www.w3.org/TR/uri-clarification/#uri-partitioning
8. "If namespace URIs were removed and namespaces were identified solely by namespace prefixes instead, namespaces would still make sense and existing XML specifications would only require minor alterations." This suggestion comes up every now and then, generally associated with a registry idea, a registry for various reasons can be problematic, please be specific as to how you wanted to solve this rather than just making pronouncements.
9."Why not just drop the URIs, admit that the namespace prefixes are significant, and end the whole pointless charade?
" followed immediately by "For XML, it may already be too late to remove namespace URIs. "
and a list of suggestions that I suppose may be helpful to someone somewhere, even if I am not exactly certain how they would be helpful.
Michael Day has a very nice product in YesLogic Prince, I would have appreciated more articles on printing in xml and printing technologies. But this article seems very poorly put together on an admittedly wide and problematic subject.
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