The site does not have good content. It attempts to explain a rather badly defined technical term, and the terms you need to understand it in 250 words (most sites would spread this across several articles).
As far as I can see it ranks only for the the two word phrase I originally found it with, and the same phrase with a third word added.
U understand toolbar BR is approximate, but I am talking about toolbar PR, and the majestic metrics and strong brands on competing sites.
Some of the pages it beats are on strong domains and one has a lot of back-links. I do not think that 2 and 3 are enough to account for it given that competing pages also have strong incoming links - especially the major news magazine with an article with title "the rise of [phrase]" and lots of external links directly to the page.
Its links include one from another one page site for a related term with the same ownership, and none of those I have found are that strong.
It does prove that a one page site with an exact match domain, little content, and a relatively small number of linking domains can rank very well.