I am always looking for information about technology that is library-specific or that has a library perspective. For Web Services and Service-Oriented Architecture (SOA), there are not many resources of that type. I was interested therefore to read
Library Technology Reports, May/June 2006, Vol. 42, No. 3, ISSN 0024-2586
Web Services and the Service-Oriented Architecture by Marshall Breeding
There are three main sections in this 52-page report. The first provides Basic Concepts, the middle provides a brief intro to Google and Amazon Web Services and how to write Perl code to use them, and at the end Breeding looks at what library groups and technology vendors are doing with Web Services. Although there a brief mention of SOA, I wouldn't consider this an intro to SOA; it's basically entirely about WS.
It starts off strong, the Basic Concepts description of Web Services from pages 6-9 is very clear and gave me a lot of useful ideas to use for explaining WS. After that it starts to get quite technical, providing brief intros to XML, SOAP, WSDL, UDDI and so forth.
For the programming section, I'm not so enthusiastic. These concepts are so complex that they really need a combination of Internet and book-length resources. This report will give you at best a tiny and perhaps confusing taste of Web Services coding.
The last section tries to cover Web Services in the Library Environment, but hits some challenges because the topic is so new. There is a discussion of VIEWS and the NISO working group it turned into. Then there's a problem because there aren't really many Web Services running - he covers SRU/SRW and SUSHI, but there's also a bunch of non-WS library tech thrown in. He ends by surveying library technology vendors on their use of Web Services.
(Note: I will review the NISO Web Service guidelines in my next post.)
My opinion overall is that it was a worthy effort, but it tries to reach too many different communities. The mix of basic concepts, coding, and industry survey ends up delivering three quite disparate pieces, each of them to some extent receiving short shrift. I could see a CIO benefiting from the basic concepts and library environment overviews. For most other staff, the basic concepts gets way too technical.
The coding section I think is the weakest, simply because there is nowhere near enough space to devote to this topic. A programmer would be much better off getting some O'Reilly books (and/or a Safari account) along with using web examples.
The section on Library Web Services is ok, but it wasn't much use to me since I already independently gathered much of the same information, and more. (See library Web Services - are we making any progress?) I was surprised that there was no mention of the Digital Library Federation services initiatives. The vendor survey was a bit useful if you're vendor-bound, but I don't think we can look to most vendors to innovate in this area.
I think it would have been better to spend more time on the basic concepts, and talk a lot more about SOA. This guide really doesn't provide any intro to SOA, it's all about Web Services. So I would have cut out the coding part entirely, except for maybe a brief intro with pointers to web resources, and expanded the basic concepts section, perhaps with some diagrams (this report has only text).
Overall I was a bit disappointed, at US$63 for 52 pages, this is a pretty expensive document.