The PCT "makes it possible to seek patent protection for an invention simultaneously in each of a large number of countries by filing an 'international' patent application." The Treaty, regs under the treaty and the signatories to the treaty are posted in the Publications section of the WIPO Web site, along with a list of the Contracting Parties and other PCT Resources. The Treaty is also posted by The Multilaterals Project with regulations.
WIPO's PCT Database lets you search the first page information of PCT (Patent Cooperation Treaty) applications for free (http://pctgazette.wipo.int). This WIPO Web site also lets you search an electronic version of the PCT Gazette, which publishes the first page of all PCT applications back to April 2, 1998. (For other free and fee-based systems that search PCT applications, see "Patents - Foreign.")