WolframAlpha (W|A for short) is an online knowledge search and calculation engine developed by WolframResearch the developer of MathematicaSoftware?.
It has just (2009-05-17) opened to the public but is still a bit beta. It already provides a lot of 'kurated' information. But contrary to what I hoped it does not allow to interrelate the information. Or I'm too stupid to figure it out. Or that's one of the pay-for ueber features. The Mathematica core should well be able to do it. And very nice interrelations and graphs are produced for some special cases. This is also one of the often repeated wishes in the W|A community boards.
CategorySearch? CategorySoftwareTool