| ID | Name | Type |
|---|---|---|
| #21925 | Atomic Projects | P |
| #1373 | Atomica | ? |
| #1374 | Atrox Programming Co | Z |
| #1375 | Attempto Verlag | ? |
| #1376 | Attila Kertesz | ? |
| #22907 | Audio Computing | Z |
| #1378 | Audio Visual Magic | Z |
| #1379 | Audio-Visual | Z |
| #1380 | Audiogenic Ltd | Z |
| #1381 | Audiogenic Software Ltd | P |
| #1382 | Audrey Bishop | + |
| #1383 | Audrey Driggs | + |
| #1384 | Audrey Meredith | + |
| #1385 | Augen Blick | ? |
| #1386 | Augusto Cervera | + |
| #1387 | Augusto Osorio | + |
| #1388 | Augusto Ruiz | ? |
| #1389 | Augustus J. Quillinan | + |
| #1390 | Aulis-Verlag | Z |
| #1391 | Aurelio Biedma Gil | + |