Rensselaer Polytechnic Institute, or RPI, is a private research university located in Troy, New York, United States. It was founded in 1824 by Stephen Van Rensselaer for the "application of science to the common purposes of life", and is the oldest technological university in the English-speaking world. Built on a hillside, RPI's 275-acre (111 ha) campus overlooks the historic city of Troy and the Hudson River and is a blend of traditional and modern architecture. The institute operates an on-campus business incubator and the 1,250-acre (510 ha) Rensselaer Technology Park, and is known for its success in the transfer of technology from the laboratory to the marketplace.