Danny Sullivan did a talk a few years ago on the evolution of search, it’s worthwhile taking 9 minutes out as he plots it:
Library/librarian – whilst web search has become ubiquitous there are still people graduating from library studies courses. The role of librarian still brings a lot to the table
The electronic catalogue for library augmented the work of librarians and allowed library users to do at least some searches themselves
LexisNexis database – proprietary business databases augmented the work of lawyers and financiers
Yahoo! – created a curated guide to the nascent web. It started off as a list of links and then got categorised over time. It is surprising how long the Yahoo! directory lasted for into the age of search.
WebCrawler – automated the process of finding websites and exploring their content which then opens up the door for modern search as we know it.
Modern search engine progress can be seen as the rapid transition between pre-eminent engines in a relatively short time. You also saw specialist tech companies like Inktomi sell web search hardware upon which media companies built their services. Yes, Google built the pre-eminent search engine, but it wouldn’t have been possible to keep going if others hadn’t come up with the crucial pieces of the online search advertising model. That’s why you see a transition from InfoSeek > AltaVista > Ask Jeeves > Google in the evolution of search. More posts on Google here.