Multilaterals Project. Fletcher School of Law and Diplomacy, Tufts University. A searchable database of multilateral treaties and other international agreements, organized by subject.
EISIL: Electronic Informations System for International Law. From the American Society of International Law, "EISIL has been designed as an open database of authenticated primary and other materials across the breadth of international law, which until now have been scattered in libraries, archives and specialized web sites."
International Agreements Collection from the U.S. Department of State's Freedom of Information Act Electronic Reading Room. The full text of recent (from approximately 1994 to date) international agreements to which the U.S. is a party. Select the box for "International Agreements" and click on "Search" to display all records. You may also search for agreements by words or phrases.