World Intellectual Property Organization (WIPO) is an agency of the United Nations. From the WIPO website:
"WIPO is the global forum for intellectual property services, policy, information and cooperation. We are a self-funding agency of the United Nations, with 187 member states.
Our mission is to lead the development of a balanced and effective international intellectual property (IP) system that enables innovation and creativity for the benefit of all. Our mandate, governing bodies and procedures are set out in the WIPO Convention, which established WIPO in 1967."
Many countries maintain their own patent databases, whether or not the patent is recognized globally with a WO prefix (filed under WIPO's PCT). It is possible for a patent to have both a WO prefix and then a separate (but most likely identical) patent issued by a country agency. Each country is given a two-letter prefix (for example, United States = US).
Some patents are not filed globally and therefore you may need to search an individual country's database.
Not all countries are listed below. If you need to find a country not listed below, go to the Directory of Intellectual Property Offices link under the WIPO box to the left.
Patents from Europe can be filled either with an individual country, the European Patent Office (EPO), or through PCT.
EPO maintains a database named Espacenet. Espacenet provides coverage for: