PageRank Update by Google
The original PageRank patent, assigned to Stanford University, has expired. Google had an exclusive license to use PageRank. Google filed a PageRank update, with a different algorithm behind it. The PageRank patent filed by Google has been updated. It does cover PageRank, as it describes in the description to the patent which tells us this about PageRank:
A popular search engine developed by Google Inc. of Mountain View, Calif. uses PageRank.RTM. as a page-quality metric for efficiently guiding the processes of web crawling, index selection, and web page ranking. Generally, the PageRank technique computes and assigns a PageRank score to each web page it encounters on the web, wherein the PageRank score serves as a measure of the relative quality of a given web page with respect to other web pages. PageRank generally ensures that important and high-quality web pages receive high PageRank scores, which enables a search engine to efficiently rank the search results based on their associated PageRank scores.
A continuation patent showing a PageRank update was granted today. The original version of this PageRank patent was filed in 2006 and reminded me a lot of Yahoo’s TrustRank (which is cited by the patent’s applicants as one of a large number of documents that this new version of the patent is based upon.)