 Data are compiled from the scientific literature by PetDB data managers, as well as being provided by members of the scientific community.PetDB is administered by the EarthChem group under the IEDA facility at LDEO headed by K. Lehnert.PetDB is supported by the U.S. National Science Foundation.Development of PetDB began in 1995 when scientists from the Lamont-Doherty Earth Observatory (LDEO) C. Langmuir (now at Harvard University), W. Ryan, and A. Boulanger saw the potential impact of new information technologies such as the World Wide Web and relational databases on the use of scientific data in research and in the classroom.