- Patents from the United States Patent & Trademark Office
- The database includes information about all US patents (including utility, design, reissue, plant patents and SIR documents) from the first patent issued in 1790 to the most recent issue week.
- Patents: International Patents: esp@cenet®
- Provides links to fulltext patents from 63 countries including the United States, Germany, United Kingdom, France, Austria, and Canada.
- Paterra - Patent Information
(Paterra, Inc. in Pennsylvania)
- Paterra has several free resources for searching patents. They also provide a fee-based translation service "InstantMT Translation" for patents in a foreign language.