The Cuil search engine is no more. It was shut down on the 17th of September. I just tried using it and when it didn't respond, I hit Wikipedia and learned it was shut down.
When Cuil first started a couple of years ago, its search results were pathetic. It had an awkward format for results and was not easy to view like other search engines. It was not ready for prime time.
A few months ago, I did several searches on Cuil to test it out after not using it for a long time. The search results improved dramatically. I was pleasantly surprised. None of my sites ranked high, but the results were mostly relevant. So it was progressing in the right direction.
I think Cuil was introduced to the public long before it was ready and this harmed its image severely. I don't like seeing any company dominate the internet because the more competition there is, the better it is for all of us. I think if Facebook were to start a search engine they could be a formidable competitor with Google due to their huge user base. They would have to provide decent results, which goes without saying. Facebook could use a search engine to drive an advertising network to rival Google. Facebook has the market value to attain the capital to try.
I would love to see someone dethrone Google.