.??_  Files ending in "_" are often compressed install files of the same
          name (e.g., .EX_ expands to .EXE, .DL_ expands to .DLL, etc.)
  .B    Limbo Implementation File (Inferno OS)
        Brainf*ck Program (small programming language)
        Befunge Program
        Applause Batch List
  .B02  ADP Payroll (unverified)
  .B16  PCO Graphic  [XnView]
  .B1J  BookJones
  .B1N  1st Reader Binary Screen Image
  .B1S  BookSmith
  .B30  Ventura Publisher Printer Font
  .B3D  3D Builder File
        BDE Multipath Movie Digital Viewer
  .B4   Helix Nuts and Bolts File (Helix Software now part of McAfee)
  .B5S  Numerical Controlled Machine File (Ball-bar?)
  .B64  Base 64 MIME-encoded File  [MIME]
  .B8   Piclab Raw Graphic File
  .B&W  Atari Black and White Graphics
        1st Reader Mono Binary Screen Image
        Image Lab  [XnView]
  .B_W  Atari/Macintosh Black and White Graphic
        1st Reader Mono Binary Screen Image
        Image Lab  [XnView]
  .BAC  Backup
  .BAD  Rime Mailer Address File
        Oracle BAD File
        Brutus Application Definition File (password cracking)
  .BAG  PMMail Mail Index File
        OS/2 Netfinity Manager Sysinfo File (adapter.bag)
        AOL Instant Messenger File
        Emperor: Battle for Dune Archive  [Dragon UnPACKer]
  .BAK  Backup
  .BAL  Ballade Music Score
  .BAN  Sierra Print Artist Banner
  .BAR  dBase Application Generator Horizontal Menu Object
  .BAS  BASIC Language Source
        Basic Module
  .BAT  Batch Processing (DOS Batch File)
  .BB   Papyrus Database Backup
        Blitz Basic File
        Starfleet Battles DOS Game
  .BB2  XBBS-OS/2, XGROUP, AV and ZTree Archiver Control File
  .BBL  TeX/BibTeX Bibliographic Reference File
  .BBM  Deluxe Paint Image File
  .BBMA  Bonzibuddy
  .BBP  BitBeamer Split File (of the form .??_??.bbp)
  .BBQ  BitBeamer Transfer Queue File
  .BBS  Bulletin Board Sytem Text
  .BC   Sierra Print Artist Business Card
  .BC3  Fiebdc-3 Format File (Format of Interchange ESTANDAR of Data bases of CONSTRUCTION)
  .BCC  Calendar Creator 8 Collection
  .BCF  ConfigSafe Snapshot Index
        The Sims (Maxis) 3D Body Mesh File
  .BCH  dBase Application Generator Batch Process Object
        Datalex EntryPoint 90 Data File
        Phoenix Software (Datalex) Entry Point 90 Data File
  .BCK  Backup
  .BCM  MS Works Communications File
  .BCN  Business Card Pro Design
  .BCO  Bitstream Fontware File
  .BCP  Borland C++ Makefile
  .BCW  Borland C++ 4.5 Environment Settings
  .BDB  MS Works Dababase File
  .BDE  Borland Database Engine (embedded in many different programs)
  .BDF  West Point Bridge Designer File
  .BDF  Egret Data File
        X11 Bitmap Distribution Format
        Backup To CD-RW Backup Definition File
  .BDG  Badge Designer 2000 Photo ID
  .BDR  MS Publisher Border [Buy Office XP at Shop.Microsoft]
  .BEC  Break Even Calculator
  .BED  InfoSnorkel Blue Elephant Definition (define content InfoSnorkel extracts from web page)
  .BEZ  Bitstream Fontware File
  .BF   Brainf*ck Program (small programming language)
        Befunge Program
  .BF2  Bradford 2 Font
  .BFA  Blowfish-encrypted File (Extension added to original) [Program List]
  .BFC  Briefcase File
  .BFF  AIX® Backup File Format
  .BFFM  B17 Flying Fortress Game File (link is to support page)
  .BFL  Colin McRae Rally 2 Data File
        BFLI  [XnView]
  .BFLI  BFLI  [XnView]
  .BFM  UNIX Font Metrics File
  .BFX  BitFax Document
        BFX Bitware  [XnView]
  .BG   MS Backgammon for Windows Game
  .BGA  OS/2 Graphic Array  [XnView]
  .BGB  MS Chat Background Graphic
  .BGI  Borland Graphic Interface
  .BGL  Flight Simulator Scenery File
  .BGM  Jane's Combat Simulations F-15
  .BH   BlackHole Archive Format File [ZipTV]
  .BHF  pcAnywhere Host File
  .BHTML  BabuHTML Embedded Software File (example use: netMailshar)
  .BHX  Archive File
  .BI   Binary File
        Progress Database Before Image File
  .BIB  Bibliography
        Papyrus Database
        TeX/BibTeX Literature Database
  .BIC  Civilization III Scenario
  .BID  BidMaker 2002 File (software to aid in making bids on jobs)
  .BIE  JBIG File  [XnView]
  .BIF  GroupWise Initialization File
        Image Capture Board Binary Black & White Image
        Baldur's Gate Archive  [Dragon UnPACKer]
        Planescape: Torment Archive  [Dragon UnPACKer]
  .BIG  Chinese (old version)
        Cartes Michelin  [XnView]
  .BIK  BioCharter Profile Backup File
        Bink Game Video File
  .BIN  Binary File (many)
  .BIO  BioCharter Profile File
        OS/2 Bios File
  .BIT  Bitmap Image
        Worms Armageddon Imported Map
        Worms World Party Imported Map
  .BIZ  Broderbund Print Shop Business Card File
  .BJF  NTI Backup NOW! File
  .BK   Backup
        LinguAssist File
        JetFax Faxbook File
  .BK!  Backup
  .BK$  Backup
  .BK?  Backup (Can be 1 to 9, usually with WordPerfect)
  .BK1  Bach Preludes and Fugues MIDI akmi Source, Book 1
  .BK2  Bach Preludes and Fugues MIDI akmi Source, Book 2
  .BKF  Moto Racer Archive  [Dragon UnPACKer]
        MS WindowsXP Backup Utility (Note: This is default; can be renamed to any extension.)
  .BKG  Background File (used in many games/programs)
        UWXAFS Binary Format Data File (absorption data on an energy grid which does not need to be evenly spaced)
  .BKI  Backup Index
  .BKP  Backup
  .BKS  Bookshelf Backup
        IBM BookManager Read Bookshelf
        MS Works Spreadsheet Backup
  .BKU  Timeslips Backup
  .BKW  FontEdit Fontset Mirror Image
  .BLA  Blat E-mail (command line E-mail tool written for Windows)
  .BLB  DreamWorks Resource Archive
  .BLD  BASIC Bload Graphics
        MegaPaint  [XnView]
        VersaPro Block Build Info
  .BLEND  Blender 3D File
  .BLG  Windows Binary Performance Log
          (W-2000 & W-XP have different formats. To convert click.)
  .BLK  WordPerfect Temp File
        Lightscape Block Library
        Alias Wavefront Image
        Amiga IFF  [XnView]
        VersaPro Block
  .BLL  An extension used by the VBS/European-A worm. If found in the directory
          C:\STARTUP suspect you are infected with this worm and have your computer
          checked with anti-virus software!
        INPRISE Format Language Library (changed to .BTL)
  .BLT  Wordperfect for DOS File
        Saved AIM Buddy List File
  .BLZ  Bitmap Graphic
        Twinkle Bulbs Bulb File
        Emblaze.Creator File
        Blazon Heraldic Shield
        Serial Number File [IBM's Drive Fitness Test (DFT) program]
  .BM   Bitmap Graphic
  .BM1  Apogee BioMenace Data File
  .BMF  Corel Flow Image File  [XnView]
  .BMI  Buzz Instrument
        Blue Martini Import File (eCRM)
  .BMK  Help Bookmark
  .BMP  Windows OS/2 Bitmap Graphics  [IrfanView]
  .BMS  Backup Magic Backup Set
  .BMU  Music/Sound File [Open with Winamp or other MP3 player]
  .BMW  Buzz Music File with Waves
  .BMX  Buzz Music File
        Siemens Mobile Phone Animation
  .BMZ  Demon Stalkers: Raid on Doomfane (old game)
  .BN   AdLib Instrument Bank
  .BNG  [Used by program RANGER.EXE] (Marshalling Yard Calculations)
  .BNK  Adlib Instrument Bank
        SimCity Game File
        (reported to be) Bink Compressed Video/Audio File
  .BNR  Binary News Reader File
  .BNSKIN  Beatnik Clock Skin
  .BOB  BobDown Downloading Program  [Also see Antibob]
        Bob Raytracer  [XnView]
  .BOL  MS Booasm Compressed Archive Library
  .BOM  Orcad Schematic Capture Bill of Materials File
        Softshare Delta Business Object Model
  .BOO  Image File
        Compressed Archive File
  .BOS  Brotherhood of Steel Compressed File (renamed ZIP file; use any extractor)
  .BOT  Frogbot Editor (Frog = Quake add-on computer opponent)
  .BOW  Back Orifice 2K Workspace [this is a hacking tool]
  .BOX  Notes Mailbox
        Lemmings Revolution Archive  [Dragon UnPACKer]
        ThrottleBox Multimedia Viewer
        Aladdin Knowledge Systems Vbox Helper Application File (software distribution)
  .BOXR  Boxerjam Interactive Game System
  .BPC  Business Plan Toolkit Chart
        BuildPro File
  .BPL  Delphi Library
  .BPP  MUSICMATCH Burner Plus Project
  .BPR  Borland C++ Builder 6 Project
        BackupXpressPro Project File
  .BPS  MS Works Document
        Bulletproof FTP Settings
  .BPT  Bitmap Master File
  .BPX  Truevision Targa Bitmap  [XnView]
  .BQY  BrioQuery File
  .BR   Bridge Script
        The Playa File (link is tentative)
  .BR3  Bryce 3D Scene File (Bryce made by MetaCreations, changed to Viewpoint, product taken over by Corel)
  .BR4  Bryce 4 File (Bryce made by MetaCreations, changed to Viewpoint, product taken over by Corel)
  .BRC  Bryce 2 Scene File (Bryce made by MetaCreations, changed to Viewpoint, product taken over by Corel)
  .BRD  EAGLE Board File
  .BRI  Basic Rate Interface File
  .BRK  Brooktrout Fax-Mail File  [XnView]
  .BRO  Tree Professional Broadleaf Creator File
  .BRP  Tree Professional Broadleaf Creator Image
  .BRS  Corel Paint Classic File
  .BRT  Brooktrout Fax-Mail File  [XnView]
  .BRU  Brutus Restore File (password cracking)
  .BRW  Application file associated with financial institution(s) loan applications
  .BRX  Multimedia Browsing Index
  .BRZ  DbBRZ File (Backup or Restore)
  .BS   Printfox/Pagefox  [XnView]
  .BS_  MS Bookshelf Find Menu Shell Extension
  .BS1  Apogee Blake Stone Data File
  .BS2  Basic Stamp 2 Code File (WordPad or BS2-Editor)
  .BSA  BSARC Compressed Archive
  .BSB  SWAT Sub-basin Output File (river basin scale model)
        MapInfo Sea Chart
  .BSC  Apple II Compressed Archive
        Source Browser Database
        Fortran Pwbrmake Object [FORTRAN]
        Boyan Script
        MS Developer Studio Browser File
  .BSK  Bryce 4 File
  .BSP  Quake Map
        Half-life/TFC/CS Map
  .BST  BibTeX Style File
  .BSU  Brindys BriTray (software update)
  .BSV  BASIC Bsave Graphics
  .BTAB  Base Guitar Tabulature [On-line Guitar Archive]
  .BTL  INPRISE Format Language Library (changed from .BLL)
  .BTM  4DOS Batch To Memory Batch File
  .BTN  ButtonWare File
        JustButtons Animated Bitmap  [XnView]
  .BTO  Baytex Organix! 2001 Language Kit
  .BTR  Btrieve Database File
        MS Frontpage-related File [Buy Office XP at Shop.Microsoft]
  .BTS  Creative Digital Blaster Digital VCR File
  .BUD  Quicken Backup
  .BUF  WinXL File  (Datascope emulation software)
  .BUG  Bug (Problem) File
  .BUL  Holiday Lights Screen Saver Bulb File
  .BUM  Poser Bump  [XnView]
  .BUN  CakeWalk Audio Bundle File
  .BUP  Backup DVD Info File
        PC-Bibliothek Update File
        CD Indexer
        Brother Embroidery System File
        Softcode Tracker Contact Manager Backup (Australian software no longer sold)
  .BUT  Buttons! Button Definition
  .BUY  Movie Data File
  .BV?  WordPerfect Overflow File (Can be 1 to 9)
  .BVH  Biovision Motion File [Format] (Used by Poser and other software)
  .BVS  BVS Solitaire Collection
  .BW   SGI Black and White Image
        Silicon Graphics Raw RGB File  [XnView]
  .BWB  Visual Baler Spreadsheet File
  .BWI  Blindread/Blindwrite
  .BWR  Kermit Beware Bug List
  .BWS  Blindread/Blindwrite
  .BWT  Blindread/Blindwrite [Fantom CD Emulator]
        CDmage Table of Contents
  .BWV  Business Wave File
  .BXF  Man's Best Friend Software Breeder Exchange Format
  .BXX  blaxxun Contact
  .BYU  Movie File (Shockwave)
  .BZ   Bzip UNIX Compressed File (Open using WinRAR
  .BZ2  Bzip UNIX Compressed File (Replaces .BZ) (Open using WinRAR
  .BZF  Textures and Other Information (used by various games)