For over a year developers have been asking for an API from Quora, the Q&A site that has recently exploded in popularity. The company had been waiting until there were "enough users and content on Quora." A browser extension outed the interface and now there is an officially released, but still alpha Quora API.
Quora co-founder Charlie Cheever commented on an API question in December 2009:
When there are enough users and content on Quora that an API would be really useful, we'll almost certainly add one.
For right now, we'll probably focus on the web interface since that's how we think most people will use the product, at least to start. Another reason we probably won't do an API for a little while is that the interface into the product is changing frequently in big ways right now (ex. We added "thanks" a few days ago and we're not sure if we'll keep that or not,) and APIs that aren't stable are hard to use effectively.
Hence, the "alpha" aspect of the new Quora API, which is being called an extension API by Quora Engineer Edmond Lau. Though Quora's popularity has expanded since the question was posted, it still expects its web interface to evolve. "Wait as long as possible" to release an API, commented former Facebook Senior Platform Manager Dave Morin. Morin ended the comment with a smiley face, but he's probably serious. Morin's latest startup Path hasn't launched an API of its own.
Quora's API could almost be classified as unofficial, much like the Instagram API, which was reverse engineered from its iPhone app. The Quora API was discovered because of a browser extension that used it, but the company quickly claimed the service.
Quora's web service was long closed to search engines and only available by invite. Perhaps this early exclusivity made it possible to get "opened kimono" answers, a tradition that continues today, especially among tech entrepreneurs. Almost a year ago, actor Ashton Kutcher let out Twitter's developer conference date in an answer on Quora.