| C2V | Enschede, Netherlands |
| Cabot Corp. | Boston, Massachusetts, United States |
| Cabot Microelectronics Corp. | Aurora, Illinois, United States |
| CAD-FEM GmbH | Munich, Germany |
| Cadence Design Systems | San Jose, California, United States |
| CalciTech Ltd. | Ferney-Voltaire, France |
| Calibrant Biosystems | Rockville, Maryland, United States |
| Calient Networks | San Jose, California, United States |
| California Fine Wire Co. | Grover Beach, California, United States |
| California Institute of Technology - Materials Science | Pasadena, California, United States |