So i've been writing my own keyword research tool for my own use lately. And I want to display PageRank results for URL's. But my question is, where are all these programs getting this information? For example: the SEO Toolbar for Firefox displays PR Market Samurai displays PR and (since i'm writing my program in Delphi), this plugin too displays PR http://www.irnis.net/soft/pagerank/ And it does a pretty good job too. But what method are the above 3 applications getting this info???