I would like to chime in on the side of those who view of GILS as more of a value system than a technology.
For me, the key value has been that societies would keep faith with traditional practice and the amazing worldwide interoperability of library catalog searching, even as cheap and seductive Internet techniques seemed to make bibliographic cataloging look "old hat".
Governments of open societies, in particular, would institute law and policy supporting the essential notion that archives, libraries, and Internet resources be treated not as separate worlds but as a synergistic continuum of resources that can be leveraged at fairly low cost in comparison to the profound benefits.
Right now we are seeing hundreds of stories about how major Web search providers have joined forces with libraries and archives to digitize books and to make all that content directly accessible from the Web. This recent development promises to give a boost to the free flow of information worldwide, and should greatly enhance public access to government information as well. To me, this is all about realizing a Global Information Locator Service.
Even a few weeks ago, many experts would have said governments have to make a choice: either take advantage of exciting and cost-effective Web search technologies, or keep faith with traditional library and archive publishing. We've heard state governments and national governments saying it over and over again--the Web folks staked out their own technological territories for public access to government information and the Library folks staked out their traditional approaches. Visits across the cyber border were infrequent and usually short-lived.
Suddenly, we see the technology leaders of the Web moving their stakes and homesteading way over there in Library territory! And, don't assume libraries are being overrun by uncivilized hordes--Web search technologies today are so close to library search technology that this territorial merger is likely to be a win-win proposition all around.
Here I need to draw attention to the unsung "technology heroes" who have been quietly chipping away to lower the technical barriers between these seemingly incompatible approaches to information search and retrieval. To my mind, the Z39.50 technology wizards should get most of the credit for preserving civilization when it teetered on the brink of "information disintegration" this decade past. Their technical prowess is remarkable but no less than their willingness to just keep at it year after year.