Functionally Z39.50 is a richer protocol, although the intent is to
include much of this in future versions of SRW if SRW is a success.

The motivations for SRW vary amongst the various people working on SRW.
I'll try to cover most of these, although this will be biases towards my
own views! I've copied this to the main SRW developers list in case they
wish to add (or contradict) what I say.

i) Basing SRW on WebServices and SOAP allows the protocol to be
implemented using a variety of modern toolkits. Z39.50, however, works
over ASN.1/BER which is comparatively less well known and there are
fewer toolkits. People working with Z39.50 spend quite a long time
getting to grips with the transport and encoding before even touching
the actual standard itself.

ii) In some ways, SRW is a marketing exercise to attempt to dispell the
myths that Z39.50 is necessarily complex.

iii) Although there are some notes on how to implement the whole of
Z39.50 directly over SOAP, this doesn't form a "natural" WebService.
With SRW we started from a clean sheet. It is the case that some
mistakes were made in Z39.50, some over complexities and some confusion
in areas. This is inevitable in any standard that has evolved over 10-15
years! In SRW we have the opportunity to look at every aspect of Z39.50
critically - retaining those concepts which are Z39.50's strength,
dropping those which proved not to work (or which were never really used
and just added to the complexity without adding any real benefit), and
clarifying those areas where there was potential confusion or were open
to interpretation. Something I've been keen to do is to avoid
unnecessary exceptional cases as I feel Z39.50 has far too many of these
which can catch out the novice.


> -----Original Message-----
> From: Alexei R. Olkov [mailto:[log in to unmask]] 
> Sent: Monday, April 07, 2003 12:11 PM
> To: Matthew Dovey
>  Dear Mr. Dovey.
> I'm sorry for interrupting you.
>  My name is Alexei. I'm Russian student.
>  I'm doing a research work in Library
> Protocols.
>  Can you please write me the main
> advantages of SRW-protocol,comparing
> with z39.50?
>   I would be very grateful for any
> information.
>  Thank you.
>  Best regards, Alexei R. Olkov.