File Extensions
File extensions are often used to determine the program that created the file. While users can rename files and/or associate odd extensions with particular programs, the following are some fairly standard associations.
Please let me know if you have applications not listed here, please advise so I can add them to the list.
You can click on the first letter of the extension to go to that group
$ _ 0 1 2 3 4 5 6 7 8 9 ? ~
A
C
D E F G H I J K L M N O P Q R S T U V W
X Y Z
"B"s
.B1J BookJones
.B1S BookSmith
.B3D 3D Builder File
.B4 Helix Nuts and Bolts File
.B64 Base 64 MIME-encoded File
.BAC Backup
.BAD Rime Mailer Address File
.BAK Backup
.BAS BASIC Language Source or Basic Module
.BAT Batch Processing
.BBM Image File
.BCK Backup
.BCO Bitstream Fontware File
.BDF West Point Bridge Designer File
.BEZ Bitstream Fontware File
.BFC Briefcase File
.BG Backgammon for Windows Game
.BGI Borland Graphic Interface
.BGL Flight Simulator Scenery File
.BI Binary File
.BIB Bibliography
.BIF GroupWise Initialization File
.BIG Chinese (old version)
.BIK BioCharter Profile Backup File
.BIN Binary File
.BIO BioCharter Profile File
.BIT Bitmap Image
.BK Backup
.BK! Backup
.BK$ Backup
.BK1 Backup (Can be 1 to 9)
.BKI Backup Index
.BKP Backup
.BKS Bookshelf Backup or IBM BookManager Read Bookshelf
.BLD BASIC Bload Graphics
.BLK WP Temp File
.BLT Wordperfect for DOS File
.BM Graphic (bitmap)
.BM1 Apogee BioMenace Data File
.BMF Image File
.BMI Buzz Instrument
.BMK Help Bookmark
.BMP Bitmap Graphics
.BMW Buzz Music File with Waves
.BMX Buzz Music File
.BNK Adlib Instrument Bank or SimCity Game File
.BOO Image File or Book or Compressed Archive File
.BOX Notes Mailbox
.BPL Delphi Library
.BPT Bitmap Master File
.BQY BrioQuery File
.BR3 Bryce 3D Scene File
.BRC Bryce 2 Scene File
.BRX Multimedia Browsing Index
.BS_ MS Bookshelf Find Menu Shell Extension
.BS1 Apogee Blake Stone Data File
.BSC Boyan Script or MS Developer Studio Browser File
.BSP Quake Map
.BSV BASIC Bsave Graphics
.BTM 4DOS Batch To Memory Batch File
.BTN ButtonWare File
.BUD Quicken Backup
.BUN CakeWalk Audio Bundle File
.BUP Backup
.BV1 Backup (Can be 1 to 9)
.BW SGI Black and White Image
.BYU Movie File