Microsoft WPC 2011 Exhibitor Guide: ALL
| Aastra | 339 |
| Accusoft Pegasus | 1140 |
| Acme Packet | 1138 |
| Adxstudio Inc. | 147 |
| AgilePoint, Inc. | 436 |
| Alchemy Solutions | 1226 |
| AltiGen | 636 |
| Amazon Web Services | 1026 |
| AMD – Advanced Micro Devices | 815 |
| APAC Region | RL-7 |
| Apprenda | 1207 |
| AppSense, Inc. | 905 |
| Apptix, Inc. | 1106 |
| ARGO | 1137 |
| Artesian Solutions | 1207 |
| ARX, Inc. | 943 |
| Assistance Software | 844 |
| AssureSign LLC | 248 |
| Astera Software | 1242 |
| AudioCodes, Inc. | 327 |