| ID | Name | Type |
|---|---|---|
| #18146 | Adam Short | + |
| #379 | Adam Takiel | + |
| #18669 | Adam Thornton | + |
| #380 | Adam Waring | + |
| #381 | Adam Whitham | + |
| #22366 | Adams Software | P |
| #17027 | Adams World of Software | S |
| #21936 | Adanoliva | P |
| #382 | Adapt Electronics | Z |
| #383 | Adaptors & Eliminators Ltd | Z |
| #384 | Adban de Corcy | - |
| #385 | Add-On Electronics Ltd | P |
| #386 | Add.On.Its | ? |
| #387 | Adder Publishing | Z |
| #388 | Addictive Games Ltd | P |
| #389 | Addison-Wesley Productions | Z |
| #390 | Addison-Wesley [NL] | Z |
| #391 | Addpac Electronics | H |
| #17934 | Ade Carless | - |
| #21163 | Ade Croft | + |