| Company Name | Software Titles |
|---|---|
| Atheros | 32 |
| Athletic Rules Study | 1 |
| ATI | 113 |
| ATI Research | 3 |
| ATI Technologeis | 2 |
| Ativa | 2 |
| ATK | 5 |
| Atlantic Link | 2 |
| Atlantic Records | 1 |
| Atlas | 9 |
| Atlassian | 1 |
| Atmel | 9 |
| ATO | 1 |
| Atola Technology | 2 |
| Atomix Productions | 1 |
| AtomPark Software | 3 |
| ATP | 1 |
| atPurpose | 1 |
| AtStaff | 1 |
| ATT | 15 |
| Attachmate | 14 |
| AttachmateWRQ | 2 |
| Attainment Company | 2 |
| Attansic | 2 |
| Attask | 2 |