Wolfram Alpha is live, API description online
Tim Finin, 9:59pm 15 May 2009Wolfram!Alpha is live. A document describing the Wolfram Alpha API can be found in Google’s cache.
Steve Wolfram wrote today in a blog post, Wolfram|Alpha Is Launching: Made Possible by Mathematica, on its relation to Mathematica.
“Wolfram|Alpha defines a new direction in computing—that would have simply not have been possible without Mathematica, and that in time will add some remarkable new dimensions to Mathematica itself. In terms of technology, Wolfram|Alpha is a uniquely complex software system, which has been entirely developed and deployed with Mathematica and Mathematica technologies. … When we launch Wolfram|Alpha this weekend, it will be running Mathematica on about 10,000 processor cores, using gridMathematica-based parallelism. And every single query that comes into the system will be served with webMathematica.”
And now, for a real test…

(spotted on Hacker News)
UPDATE: (5/18) The API document is officially now available.

May 19th, 2009 at 6:49 am
Not sure why you are pointing to the Google cache for the API document. It is online here: http://www.wolframalpha.com/WolframAlphaAPI.pdf
To find it click on Downloads at the top of the Wolfram|Alpha homepage, then scroll to the bottom and click For Developers.
May 19th, 2009 at 7:38 am
Thanks Owen. I’ve updated the post. When I made it this was not available except in the cache, to my knowledge.