Wolfram Alpha is a web site and also a $3.00 Android app. I’ve been working with the app for a couple days now, and the web page some of yesterday. It’s a ‘scientific knowledge base‘, and also a powerful calculator and equation solving tool. It graphs, it integrates, it differentiates, it knows what a logit is, and can convert probabilities and logits in either direction.
It knows what osmium tetroxide is, gives you the Lewis structure and the toxicology of the compound. It can tell you the mass of Jupiter in earth units, and can map, say, Betelgeuse or Rigel into a Hertzsprung-Russell diagram. It’s not suited to answering many programming questions, though its answer to ‘shell sort’ is interesting enough. Right now, in conjunction with Stats Inc, they’ve loaded 5 years of NFL data into the engine, so the question ‘Tony Romo passer rating’ returns a result. No such luck for ‘Babe Ruth on base percentage’. And don’t ask for ‘Jim Brown yards per carry’ either. It’s not in the engine currently.
It has a nice understanding of genealogy, can convert from any numerical base you like (so useful as a ‘programmers calculator’). The bases to be converted aren’t fixed, though base conversions of any kind give you the number in binary, octal, and hex as a by-product. In theory, you could do Mayan (base 20) or Babylonian (base 60) math.