In March, 2009, Wolfram Research announced the availability of a socalled "Computational Knowledge Engine".
It's the brainchild of physicist, mathematician, author and businessman Stephen Wolfram.
>Another google?
Not exactly. You ask a question and WolframAlpha searches trillions of pieces of stored data to "compute" an answer.
Google, on the other hand, provides internet links which (may) provide the answer. Google had a huge library of web site addresses associated with words that you enter.
WolframAlpha gives all the hard work to Mathematica
(initially released in 1998).
Mathematica does lots of amazing things ... for example
 
Provide google with blue sky and you get lots of stuff, like so:
 Ask Wolfram and you get this:

>Is that what you wanted?
Maybe ... maybe not. How can Wolfram know? However, if you are more specific, you can get these responses:
>I prefer google.
Remember that WolframAlpha is an infant.
Do you remember google ... as an infant?
(Google began life in a garage, in 1998, in Menlo Park, California.)
 
One of these days you'll be pleasantly surprised at the answers that WolframAlpha gives.
It'll be (eventually) a global brain, searching its data base, associating one thing with another and finding relationships
... then "computing" an answer as in Artificial Intelligence.
>So, one day, robots will incorporate Wolframtype stuff, eh?
Indubitably!
Try some of these ... keeping in mind that WolframAlpha is in early stages of development: it's alpha, not omega:
 
Some interesting things to note:
 When you ask moon, it gives not only the "average" distance, but also the "current" distance ... 'cause it changes.
 When you ask star chart, it gives the chart from your location on planet earth!
 When you ask fractal, it gives you several choices ... just in case you didn't know what choices there were.
 It has a sense of humour!!
It sometimes doesn't understand your question and misinterprets.
You ask Can you sing? and it says:
Sometimes it gets confused, like if you ask $CAD $USD it says:
(Canadian dollars to the fourth ??)
Sometimes it just talks to itself:
>Why do you always stick in that  ... as in WolframAlpha.
I asked: What is your name?
One day, soon, I suspect it'll answer: My name is WolframBeta.
An experimental Addon for Firefox^{*} is now available.
When you do a Google search, it also displays the WolframAlpha response ... like so:
* What! You don't use Firefox!?
