| Company | Location |
|---|---|
| Crystallume | Santa Clara, California, United States |
| Crystalplex Corp. | Pittsburgh, Pennsylvania, United States |
| CSIRO | Parkville, Victoria, Australia |
| CSIRO Nanotechnology Centre | Sydney, New South Wales, Australia |
| CTC Nanotechnology GmbH | Merzig, Germany |
| CTRL Systems Inc. | Westminster, Maryland, United States |
| Cube Optics AG | Mainz, Germany |
| Current Concepts LLC | Watertown, Wisconsin, United States |
| Curt Deckert Assoc. Inc. | Santa Ana, California, United States |
| Custom Control Sensors (CCS) | Chatsworth, California, United States |
