| ID | Name | Type |
|---|---|---|
| #2920 | Cyclone | Z |
| #19303 | Cygnus | - |
| #2921 | Cygnus Software | Z |
| #17202 | Cygnus Two Computer Games | S |
| #18235 | Cymon's Games | ? |
| #2922 | Cyningstan | ? |
| #2923 | Cyrehl Owl | ? |
| #20559 | Cyril Dufer | + |
| #2924 | Czerweny Electronica S.A.I.C. | Z |
| #2925 | Czes Kosniowski | + |
| #20885 | Cândido Manuel Pereira | + |
| #20384 | César Martinez-Barbosa | + |
| #22870 | Códice Soft | P |
| #20126 | D Pashley | + |
| #22031 | D Shaw | + |
| #2926 | D&H Games | P |
| #2927 | D&K Softwaredevelopments | Z |
| #2928 | D&L Research | Z |
| #19805 | D'Antón | - |
| #2929 | D-B Software | Z |