This page provides a list of those file extensions that start with .b. The information given below is a summary and further details can be found by clocking on the summary next to the file extension of interest.

.badGeneric bad (corrupt) file | Non-delivered email.
.bakGeneric backup file.
.bamlBinary XAML file.
.basBASIC source code file.
.batMS-DOS batch file.
.bbcBBC BASIC for Windows program or data file.
.bbtBTwin database file | bbTracker GPS track file | Basket Ball Team file.
.bcBCwin project file | BitComet intermediary download file | Big Crunch compressed archive | Byte Code (LLVM) file.
.bcdBoard/Chip description file.
.bckVMS backup file.
.bdbBack of Works database file.
.bdpBad mail pointer file | Combat Flight Simulator 3 file.
.bdrBad mail report file | Microsoft Publisher Border file.
.bfcWindows Briefcase file.
.bikBink Video file.
.bilSpot raster image file.
.binGeneric binary | MacBinary encoded file | CD image.
.bkAdobe FrameMaker book file.
.bkfWindows backup file.
.bkpbackup file
.bksBackup selection file.
.blkDescent Mission Builder block file.
.bmcBitmap Cache file | Embroidery image file.
.bmpBit-map image file.
.bnkDecent 2 FM sound instrument definition file.
.bpgBorland Delphi project group file.
.bplBorland package library.
.bqyBrioQuery file.
.brdLayout file for EAGLE EDA system | BizInt Smart Charts file.
.brnBrainStorm model file.
.brwProMash session file.
.bscBrowse information file.
.btBTwin project file | EVwin project file | ILwin project file.
.btkTeKton database file.
.btmBatch to memory file.
.buPegasus mail temporary file.
.budBackup disk for Quicken.
.bupBackup of a .ifo file.
.bvaBiovision action file.
.bvhBiovision hierarchical motion file.
.bvpBlueVoda Publication file.
.bz2Bzip2 compressed file.

For further information about the file extension please do click on the summary next to the file extension in the list above.

We would like this listing to be complete and comprehensive, but recognised that we may have missed one and that new file types are being used all the time. So if you know of a file type that we have missed that should be listed here then please let us know.