GG lists a number of competitor search engines, and one former competitor (Kaltix was acquired by Google). Personally, I hope Google does not take the Microsoft-approach to smaller, up-and-coming competitors.
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IITian, I almost said something about having 20 major players would be better. I think there's a ton of room for different companies in different niches, and it's good to see different philosophies and the approaches that come out of that. Kartoo/Mooter/Grokker hit different UI aspects, Teoma/Vivisimo lean toward different ways of clustering, Yahoo espouses PFI as an insurance policy to guarantee crawling, Feedster/Moreover and a ton of others lean more toward blogs or news, Eurekster is trying search+social networking, Turbo10 has got customization of which databases to search, Nutch goes for the completely open-source approach, Dipsie is evidently trying to crawl into forms and the deep web, Kaltix was playing with personalization. It's a really interesting time, and I'm glad that lots of companies are tackling different parts of search.