The former leader of the Google web spam team Matt Cutts shared, on Twitter, a few documents portraying early Google PageRank development notes and other search engine ranking information:
The document shows how Google PageRank will take into account link structure and the value of quality versus quantity of backlinks. To quote Matt:
Oh man. Looking through old stuff and found Google docs/papers I studies/annotated in ’99 from before I even joined.
It is really interesting to see how Google’s revolutionary PageRank was explained in these old documents as well as Matt’s very own notes on the subject. Keep in mind that this is before he even joined Google.