Developer Chirag Mehta wanted a better way to search Wikipedia, so he put together a fast, dynamic as-you-type search box that loads results in a sidebar and the best match in the main panel. You can also use the search engine's address—
http://chir.ag/wiki/something/ to go directly to search results (like using a Firefox keyword search). Here are the results for a search for "Lifehacker". A few Wikipedia-specific search interfaces have popped up over the years to compensate for the suckiness that is the built-in search box, and this is one of the better ones.