True Knowledge: a search engine which shows its workings

Whilst Cuil has hoovered up a great deal more press attention (one news cycle hyping it up, the next knocking it down), the lower-profile True Knowledge strikes me as a far more interesting and innovative new search product. Currently in invite-only beta, it starts from a fundamentally different premise to most search engines; that by assembling a library of verifiable facts, which can then be combined using logic rules, in can answer a wide variety of questions from its own knowledge database.

Whilst the majority of queries won't yet return a result (it is currently drawing on a database of just over 100 million facts about 4 million things) those that do give an exciting glimpse of what the product could become. For example, asking 'Who was president of the US when Barack Obama was a teenager?' shows how eleven facts have been combined to give four correct answers (pasted below, along with a couple of other examples which illustrate how True Knowledge handles ambiguity in the question by providing multiple possible answers and explaining the logic). Impressive stuff.

I have 20 True Knowledge beta invites to give away - email me (the name of this blog at gmail.com) if you'd like one.