It is developed by USPTO for patent classifier, patent searcher and examiner. It tells you where to find relevant prior act by seaching various databases. I guess USPTO spent millions of $$ per year to license these databases.

http://www.uspto.gov/web/patents/searchtemplates/

http://www.uspto.gov/web/patents/searchtemplates/class435.htm

http://www.uspto.gov/web/patents/searchtemplates/class436.htm

These two are quite similar in web design (color) but functionally different:

• FreePatentsOnline: http://www.freepatentsonline.com/
• Patentstorm: http://www.patentstorm.us/

PatentStorm is fast for browsing by inventors and by date. But most people are interested in searching by keywords or subjects. Maybe I will search their web site when I want to check how many patents my brother has filed so far.

PatentStorm is using PHP and lighttpd, based on sniffer results using curl. PatentStorm was developed by the same developer(s) from Storming Media LLC who published Congressional Staff Salaries on http://www.legistorm.com and claimed-to-be unclassified or declassified documents on http://www.stormingmedia.us.

But FreePatentsOnline has the best full-text search results and the largest user base. USPTO may have lost million of $$ (check http://www.uspto.gov/web/offices/ac/ido/oeip/catalog/prices/priclist.htm#P5200dl for price list) because users now can download patent image in PDF format for free. FreePatentsOnline offers these for free because its business is entirely dependent on Google, it is like a division of Google Inc—-it uses Adsense to make money.

But in 2007, Goggle launched its own patent search web site to compete with other small companies: http://www.google.com/patents.

Searching Google and FreePatentsOnline with keyword “PCR mix” or “PCR enhancer” return different results. Which search engine gives you more relevant information?

Other patent search web sites:

PCT Patent search: http://www.wipo.int/pctdb/en/

GB esp@cenet database: http://gb.espacenet.com

Canadian Patents Database: http://strategis.ic.gc.ca/sc_mrksv/cipo/search/exsearch-e.html

Japan Patent Office: http://www.jpo.go.jp/

Chinese Patent Office (State Intellectual Property Office of the People’’s Republic of China — SIPO): http://www.sipo.gov.cn/sipo_English/zljs/default.htm

Deutsches Patent- und Markenamt: http://www.dpma.de/index.htm

Patent Lens: http://www.patentlens.net/patentlens/simple.cgi, for patents in life science area.

Of course, USPTO’s patent search web site (http://www.uspto.gov/patft/index.html) is United States’ official patent search site, but the web site was probably developed by a government contracting company, and the project might have cost tax-payers millions of $$$.