Enter a question or calculation and Wolfram|Alpha uses its built-in algorithms and data to get the answer. A huge set of information and tons of models, methods, and algorithms that make it possible to compute whatever can be computed about anything

Collection of information about a web site, including statistics on web site traffic, usage, popularity, related sites, contact information, mailing address and more

When visiting a a web site produces a 404 or another message, check if it's that site that isn't working (down for everyone) or if it's your Internet service provider (just you).

The largest human-edited directory in the world. Also known as DMOZ.

blekko's web search uses slashtags that narrow your search to only the sites or concepts you want

Nice, clean web search results with more privacy than Google, fewer ads and spam. A little known gem.

Find out about a domain, including who owns it and their contact information, what server software it runs, usage ranking among many other useful information bits

Use the Yahoo web directory when you want to find sites specializing in a given topic or you are looking for a specific Web site home page

Yippy queries several top search engines, combines the results, and groups similar results together into groups

Check a web page's reachability and response time from 10 locations around the world. See how long it takes to look up the site's IP address from DNS, to connect (latency from a location to the site), and to receive the page's text.