> Praise:
> Thank you, thank you, thank you. I think that SRU might be 
> the killer protocol that finally makes people outside the 
> library bubble interested in implementing "our" standards. It 
> might even be possible to hire people fresh from the 
> university and have them implement it, and not recieve that 
> glazed over look that they get when you tell them about the 
> wonders of ASN.1, BER, ISO2709 ... :)

Thanks - much of that formed some of our motivations behind SRW/SRU (in
my case *the* motivations but other had different motivations)
 
> * XCQL
> Why, oh why is this necessery? If it's only used for 
> debugging, then put it somewhere else, like in the diagnostics.

There's a little bit of history here (even for such a reletively young
standard!) - some of us wanted an XML based query language so that we
could use XML tools to build and deconstruct the queries; others wanted
a string based query language (which fits better into URLs but requires
Lex/Yacc type approaches to deconstruct etc.). I favoured the XML side,
but the string people won in the end - in SRW you had to support both in
the request, now XCQL is relegated to just echoed requests in the
response.

One of the reasons behind the SRU variant is to allow thin (also know as
dumb or brain-dead) clients. These would just use XSLT to generate the
entire user interface on the fly (e.g. making us of Internet Explorer's
inbuilt support for XML and XSLT). The problem here is that XSLT is not
particularly good at deconstructing strings, so the XCQL form for
responding back is needed is the XSLT base user interface is going to do
anything clever in terms of allowing the user to refine their query etc.

Matthew