| bmrl | Balsamiq Mockups Data |
| bmsh | Edge Mesh Data |
| bmsk | STK Body Mask File |
| bn7 | OxMetrics Binary Data |
| bnb | Backnine Bookie Data |
| bnbk | BioNumerics Database Backup |
| bnd | hyperMILL CAM Boundary Data |
| bnf | Backus-Naur Form File |
| bnk | Guitar Rig Preset Bank |
| bnl | MicroSim PCBoard Netlist |
| bnn | FLUKA Binary Data |
| bnr | OS/2 MultiDesk Banner |
| bnskin | BeatNik Clock Skin |
| bntx | Switch Binary NX Texture Data |
| bnw | Bayesian Network Web Server Data |
| bnz | The Bingo Maker Card Template |
| bobj | Blender Fluid Simulation Object |
| bof | Babylon License Data |
| bog | PVVMUD Binary Object Geometry File |
| bok | Pearson TestGen Test Bank |
| bom | Mac OS X Bill of Materials File |
| bom | PTC Creo Bill of Materials File |
| bon | Binary Object Notation Document |
| bonds | Ribbons Bonds Definition |
| bones | XtalView Xfit Ridgelines Data |
| boo | Boo Encoded Data |
| book | Budget In Brief Budget Book |
| bop | Vflo Model Data |
| bopx | Vflo Model Data |
| bov | VisIt BOV File |
| bow | Back Orifice 2K Workspace |
| box | CARA Loudspeaker Design |
| box | Kodicom Video Metadata |
| bp2 | Autodesk AutoCAD Batch Plot File |
| bp3 | Autodesk AutoCAD Batch Plot File |