Several web sites deal with the various ocean drilling programs, which started in 1968 and continue today.
Deep Sea Drilling Project - the first comprehensive program to drill and retrieve cores from the floors of all oceans. This site provides access to DSDP publications and data. It found that the ocean basins are young compared to the continents, and proved some aspects of seafloor spreading and plate tectonics.
Ocean Drilling Program - the ODP succeeded the DSDP, and continued to explore Earth processes by drilling and recovering sediments from the ocean floors. This site provides information on and access to ODP publications and data.
Integrated Ocean Drilling Program - the IODP has replaced the ODP. It is an international oceanographic research program that explores Earth's history and structure based on the sedimentary record.