(Please excuse the cross-postings.)
While I am tooting my own horn here, and recording it in mailing list archives for posterity, the folks at Ariadne have published an article I wrote called "An Introduction to the Search/Retrieve URL Service (SRU)". From the article:
This article is an introduction to the "brother and sister" Web Service protocols named Search/Retrieve Web Service (SRW) and Search/Retrieve URL Service (SRU) with an emphasis on the later. More specifically, the article outlines the problems SRW/U are intended to solve, the similarities and differences between SRW and SRU, the complimentary nature of the protocols with OAI-PMH, and how SRU is being employed in a sponsored NSF (National Science Foundation) grant called OCKHAM to facilitate an alerting service. The article is seasoned with a bit of XML and Perl code to illustrate the points. If index providers were to expose their services via SRW and/or SRU, then the content of the 'hidden Web' would become more accessible and there would be less of a need to constantly re-invent the interfaces to these indexes.
http://www.ariadne.ac.uk/issue40/morgan/
I think these Web Service protocols, SRW/U, hold A LOT of promise for searching the "hidden Web". I think it behooves us folks in Library Land to implement these protocols against locally developed, Internet-accessible indexes. Since the stuff returned from queries against SRW/U implementations are pure XML it is much easier to reuse this stuff for many and varied purposes. Display. Storage. Syndication. Meta searching. Etc.
"Just give me the data!"
-- Eric Lease Morgan University Libraries of Notre Dame
