Wolfram Alpha has an API
If you are a developer and want to get your hands dirty with Wolfram Alpha – here is a link to the API documentation:
http://www.wolframalpha.com/developers.html
Not had chance to read it myself yet (in the middle of cooking for a dinner party) but would be interested in people’s thoughts.
It looks like at the moment they only have an API that allows you to make queries, just like you can make on the website, but with the API you get the output in a structured way. However it says that in the near future they plan to make available an API to let you access the curated data in a more direct way.