Okay, the cynical quip is "All search engines other than Google's are 'non-profit'." :-) But the reasons for that won't fit in the margin here. Building search

Okay, the cynical quip is "All search engines other than Google's are 'non-profit'." :-) But the reasons for that won't fit in the margin here. Building search engines are cool and fun! They have what seems like an endless source of hard problems that have to be solved before they are even close to useful! As a result people who start on this journey often end up crushed by the lack of successes between the start and the point where there is something useful. So if I may, allow me to suggest some alternatives which have all the fun of building a search engine and yet can get you to a useful place sooner. Consider a 'spam' search engine. Which is to say a crawler that you work to train on finding spammy useless web sites. Trust me when I say the current web is a "target rich environment" here. The purpose would be to not so much provide a search engine in total here, as it would be to provide something like the realtime black hole list did for email spam, come up with a list of URLs that could be easily checked with a modified DNS type server (using DNS protocol but expressly for the purpose of doing the query 'Is this URI hosting spam?' in a rapid fashion. There are two "go to market" strategies for such a site. One is a web browser plugin that would either pop up an interstitial page that said, "Don't go here, it is just spam" when someone clicked on a link. Or a monkey-script kind of thing which would add an indication to a displayed page that a link was spammy (like set the anchor display tag to blinking red or something). The second is to sell access to this service to web proxies, web filters, and Bing which could in the course of their operation simply ignore sites that appeared on your list as if they didn't exist. You will know you are successful when you are approached by shady people trying to buy you out. Another might be a "fact finding" search engine. This would be something like Wolfram Alpha but for "facts." There are lots of good AI problems here, one which develops a knowledge tree based on crawled and parsed data, and one which answers factual queries like 'capital of alaska' or 'recipe for baked alaska'. The nice things about facts is they are well protected against the claim of copyright infringement and so people really can't come after you for reproducing the fact that the speed of light is 300Mkps, even if they can prove you crawled their web site to get that fact.