| b3 | VTrain Data File |
| b3d | Blitz3D Object |
| b3dm | Cesium Batched 3D Tiles Data |
| b4 | VTrain Data File |
| b4a | Native Instruments B4 II Data |
| b4p | Native Instruments B4 II Presets Data |
| b5 | VTrain Data File |
| b64 | Base64 Encoded Data |
| b6l | BlindWrite License Data |
| b8 | Cubicomp PictureMaker Blue Channel Image Data |
| b84 | TI-84 Plus CE Bundle Image |
| bab | Babble Data |
| babl | DeBabelizer Pro Data |
| bac | Avantrix Backup Plus Backup Data |
| back | RMCProfile Coefficient Data |
| bad | Brutus Application Definition |
| bad | Microsoft Exchange Non-Delivery Report Message |
| badongo | Badongo File Info |
| bafl | BurnAware File List |
| bag | PMMail Mail Index |
| bai | Bank Administration Institute Data File |
| bap | Visage Mpeg-4 ASCII Body Animation Parameters File |
| bap | Blaze Audio Wave Information |
| baroc | IBM Tivoli Enterprise Console Adapter Description |
| bartco | Bartco VMS Message Data |
| base | BioArray Software Environment Data |
| base64 | Base64 Encoded Data |
| bash_history | Bash History Data |
| bav | The Bat! Anti-Virus Plugin |
| baw | BrainLED AlfaWave Session |
| bbd | Xilinx Black Box Definition |
| bbi | LinkOne Publisher Book Data |
| bbk | Sage Fixed Assets Database Backup |
| bbk | Treepad Database Blob Backup |
| bblx | E-Sword Bible Data |