File extensions that begin with B.
Ext. Type of file
BAK Backup
BAS BASIC source code
BAT DOS, OS/2 batch file
BFC Windows briefcase document
BIN BINary (miscellaneous)
BLX Magellan topographic data
BM1 Apogee BioMenace file
BML Bookmark library (SyncURL)
BMP Windows & OS/2 bitmap
BMK Windows help bookmarks
BMS BlackMagic script
BPD PS binary printer description
BPD FARSITE burn period (times & dates)
BRK Brooktrout fax
BS1 Apogee Blake Stone
BUP Backup to IFO file
BZ2 BZ2 compression
B64 MIME encoded (Base 64)