| Name |
Count |
Years active |
| NetLibrary | 3389 |
1992-2000 |
| Project Gutenberg | 3215 |
1994-1997, 1999-2000 |
| State University of New York Press | 2270 |
1971-2002 |
| MIT Press | 2095 |
1980-2004 |
| University of Virginia Library | 1963 |
1992-1999 |
| University of California Press | 1707 |
1941, 1951, 1967, 1970, 1973, 1980-1981, 1984-2003 |
| National Academy Press | 1287 |
1974-1975, 1981-2000, 2002 |
| Oxford University Press | 1091 |
1979, 1981-1984, 1987-2000, 2002-2004 |
| McGraw-Hill | 868 |
1963, 1975-1976, 1979, 1983, 1989-2001 |
| Indiana University Press | 742 |
1966, 1969, 1976, 1978-1980, 1982-1999 |