| .b | IBM Lotus Applause Batch List Format |
| .b!k | Microsoft Flight Simulator Scenery |
| .b&w | Bitmap Image |
| .b00 | Blindwrite |
| .b01 | BlindWrite Image |
| .b02 | BlindWrite Image |
| .b1 | B1 Compressed Archive |
| .b16 | PCO Image |
| .b2 | Progress Database |
| .b24 | Ovation Pro For RISC OS C Script |
| .b25 | Ovation Pro For RISC OS DDL |
| .b26 | Ovation Pro For RISC OS Style Sheet |
| .b27 | Ovation Pro For RISC OS Document |
| .b2a | Binary To ASCII (BTOA) Encoded Format |
| .b2d | Brutus2D Source Code |
| .b2f | RISC OS Windows Metafile |
| .b30 | Ventura Publisher Printer Font |
| .b3d | BodyPaint 3D Format |
| .b3p | Native Instruments Battery Preset |
| .b4s | Winamp 3 Playlist Format |
| .b4u | Visual ReadMe |
| .b5 | MDBG Chinese-English Dictionary |
| .b5i | BlindWrite Image Format |
| .b5l | BlindWrite Image |
| .b5t | BlindWrite Image Format |
| .b60 | RISC OS PNG Bitmap Image |
| .b64 | ASCIIi Base64 MIME Encoded Archive Format |
| .b6i | BlindWrite Image Format |
| .b6l | Blindwrite License |
| .b6t | BlindWrite Table Of Contents Format |
| .ba | Scifer Archive External Archive Format |
| .ba1 | Microsoft Windows Media Center Report Log |
| .babl | DeBabelizer |
| .bac | Backup Plus Backup Format |
| .back | RMCProfile Coefficient |
| .backup | Backup Of Current ISAPI Application |
| .backupdb | Apple Time Machine Backup Folder Format |
| .bad | Microsoft Exchange Badmail Format |
| .badongo | Badongo Information Service |
| .baf | Battlefield 2 Animation |
| .bafl | BurnAware Free Compilation Format |
| .bag | PMMail Mail Index |
| .bai | BUILD2WIN Add-in |
| .bak | Backup Plus Backup Format |
| .bak2 | Microsoft FrontPage |
| .bak3 | Crysis Backup |
| .bak~ | AbiWord Auto-saved Document Format |
| .bal | Borland Programming Language Source Code |
| .bam | Bobs Adlib Music |
| .bamboopaper | Bamboo Document |
| .bamp | Easy Button & Menu Maker Project |
| .ban | MegaHAL Non-keyword List |
| .band | GarageBand Music Project Format |
| .bap | Blaze RipEditBurn Audio Wave Information Format |
| .bar | Age Of Empires / Age Of Mythology Game Format |
| .bas | Basic Source Code Format |
| .basebinary | Apple Mac OS X AirPort Base Station Binary |
| .baseconfig | AirPort Utility Setting |
| .baseproj | DNA Baser Sequence Aligner Project |
| .baserproj | DNA Baser Project Format |
| .basex | BaseX Data Format |
| .bash | Unix Shell Script (bash) |
| .bashrc | Bash Shell Startup Script Configuration Format |
| .bash_history | Bash History Format |
| .bash_login | Unix Shell Script (bash) |
| .bash_logout | Unix Shell Script (bash) |
| .bash_profile | Bash Interactive Login Shell Format |
| .basin | HEC-HMS Basin Model Settings |
| .bat | Batch File (executable) |
| .batch | Switchball Game Data |
| .bau | OpenOffice.org Configuration Format |
| .bav | AVG Bat! Plugin Format |
| .baw | BrainLED AlfaWave Session |
| .bay | Kodak/Roper Bayer Picture Sequence Format |
| .baz | Acomba Accounting Suite Backup |
| .ba_ | Renamed BAT Format |
| .bb | Blitz Basic Source Code Format |
| .bb2 | XBBS-OS/2, XGROUP, AV, ZTree Archiver Control |
| .bb3 | BlasterBall 3 Level Format |
| .bba | BlueByte Archive |
| .bbb | BlackBerry Backup (post 2012) Format |
| .bbc | BBC BASIC For Windows |
| .bbcd | BobCAD-CAM Document |
| .bbe | MindGenius Brainbloom |
| .bbf | ScriptBasic Binary |
| .bbfw | ITunes Firmware |
| .bbg | CyberSports For Basketball Game |
| .bbi | LinkOne Data |
| .bbk | TreePad Backup |
| .bbl | TeX/BibTeX Bibliographic Reference Format |
| .bblm | Mario Kart Mod Effect Format |
| .bblx | E-Sword Bible |
| .bbproject | BBEdit Project Format |
| .bbprojectd | BBEdit Project Format |
| .bbrkpuzzle | Puzzle |
| .bbrksave | Puzzle Started Status |
| .bbs | Bulletin Board System Text Format |
| .bbt | BTwin Local Database |
| .bbtl | BBEdit Tool Palette |
| .bbv | PPLive |
| .bbw | Band-in-a-Box Nterface |
| .bbx | BrainBox Neural Network |
| .bbxt | BBEdit |
| .bbz | BeBuzz Backup Format |
| .bc | Bittorrent Unfinished Download Format |
| .bc! | Bittorrent Unfinished Download Format |
| .bc5 | Impression Document |
| .bc6 | Cashflow Manager 2006 Backup |
| .bc7 | Cashflow Manager 2007 Backup |
| .bca | Allplan Backup Catalog |
| .bcb | Borland C++ Builder |
| .bcc | Borland C++ Format/makefile |
| .bcd | Microsoft Windows Boot Configuration Format |
| .bcf | Business Card Designer Pro Business Card Design Format |
| .bch | Datalex Entrypoint 90 Data |
| .bci | Belarc Advisor Computer Profile Report |
| .bck | VMX Backup Format |
| .bckp | Ad-Aware Quarantined Format |
| .bcl | Illumina CASAVA Base Call Format |
| .bcm | Business Contact Manager Format |
| .bcmx | Microsoft Outlook Business Contact Manager Customization Format |
| .bcn | Business Card Design |
| .bcp | Borland C++ Makefile |
| .bcr | Map&guide Station List |
| .bcs | Boland Calibration Settings Format |
| .bct | Adobe Bridge Cache Format |
| .bcw | Borland C++ Workspace |
| .bcx | Beam Report Standard Definition |
| .bd | BenDaglish Audio |
| .bd1 | Map Block Location |
| .bd2 | Lacerte Tax Tax |
| .bdae | Gameloft Game Data Format |
| .bdb | Microsoft Works Database Backup Format |
| .bdb2 | BrainMaster Settings |
| .bdc | Lingvo Dictionary Format |
| .bdcm | Microsoft Visual Studio BDC Model |
| .bdcr | Microsoft Visual Studio BDC Resource |
| .bdct | BBEdit Dictionary |
| .bdd | CARA Sound Radiation Data Format |
| .bde | Pro/ENGINEER Temporary |
| .bdf | Bdiff Bupdate Binary Update Format |
| .bdg | Badge Designer 2000 Photo ID |
| .bdh | Silk Performer Include |
| .bdi | Pro/ENGINEER Temporary |
| .bdic | Google Chrome Dictionary Format |
| .bdjo | Java BD-J Object Descriptor |
| .bdk | OS/2 Floppy Disk Image |
| .bdl | CoCreate Designer Bundle Format |
| .bdm | AVHCD Video Information Or Index Format |
| .bdmv | Blu-ray Information Format |
| .bdoc | DigiDoc Client Container |
| .bdof | Mario Kart Mod Effect |
| .bdp | Microsoft Exchange Diagnostic Message |
| .bdr | Microsoft Publisher Border Format |
| .bds | Cadcorp SIS Base Dataset |
| .bdsgroup | BDS Project Group |
| .bdsproj | BDS Project Format |
| .bdt | Lingvo Dictionary |
| .bdt2 | BEEDOCS Timeline 3D Timeline Document Format |
| .bdt3 | BEEDOCS Timeline 3D Timeline Document Format |
| .bdtd | Java Sun Binary DTD |
| .bdtp | BaiduPlayer Media |
| .bdv | BitDefender Vault |
| .bdw | Budget Data |
| .bdx | BitDefender |
| .bdy | DMAP Boundary |
| .bea | Beamer Song |
| .beam | Compiled Erlang Code Format |
| .bean | Bean Document Format |
| .beb | EEC Analyzer |
| .bed | UCSC BED Annotation Track Format |
| .bee | Bee Archiver Compressed Archive |
| .beh | CRiSP Calibration |
| .bejeweled2deluxesavedgame | Bejeweled 2 Deluxe Save Game Format |
| .bek | Shanda Bambook E-book |
| .bel | Belon Compressed Archive |
| .ben | SiSoftware Sandra |
| .bep | Beamer Playlist |
| .bes | MOBY Database |
| .bet | BETA Source Format |
| .bevel | FontTwister Bevel |
| .bex | BOOM Extensions To Dehacked |
| .bexpk | PGP Binary Extracted Public Key |
| .bf | Beyond Good & Evil Game Archive Format |
| .bfa | Blowfish-encrypted Format |
| .bfb | Zoo Tycoon 2 Game Model |
| .bfc | Microsoft Windows 95 Briefcase Document Format |
| .bfd | Linux BFD Rules Configuration |
| .bfe | Bcrypt - BlowFish File Encryption |
| .bff | AIX Backup Format |
| .bffm | B-17 Flying Fortress: The Mighty 8th Game |
| .bfg | Mario Kart Mod Effect Format |
| .bfi | Blaise Index |
| .bfl | Colin McRae Rally 2 Game |
| .bfli | BFLI Image Format |
| .bfm | Terminal Reality Model Format |
| .bfmv | BfMeshView Workspace |
| .bfont | Need For Speed SHIFT Font |
| .bfp | Benchmark Factory Project |
| .bfr | Network Instruments Observer |
| .bfs | SmartWare Backup Sort Definition Format |
| .bft | SmartWare Backup Transaction Definition |
| .bfw | SmartWare Backup Cross-tab |
| .bfx | Bitware BitFax Format |
| .bga | OS/2 Graphic Array |
| .bgcf | Greeting Card Design |
| .bgd | ESRI Binary Raster Definition |
| .bgeo | Houdini Binary Geometry Format |
| .bgf | ZEMAX Binary Glass Catalog |
| .bgi | BGInfo Configuration Format |
| .bgl | Microsoft Flight Simulator Scenery Data Format |
| .bgm | Basic4GL 3D Object |
| .bgo | Bigoven Recipe Card |
| .bgr | Girder Binary Plugin |
| .bgt | Graphic Accounts Account Data Format |
| .bgui | Need For Speed SHIFT GUI |
| .bgv | BonanzaGraf Financial Presentation |
| .bgw | Final Fantasy Music |
| .bgz | Blood Frontier Map Format |
| .bh | ZipTV BlakHole Archive File Format |
| .bh3 | Rise Of Nations Unit Graphic |
| .bha | Rise Of Nations Unit Graphic |
| .bhf | PcAnywhere Host |
| .bho | Behold Settings Format |
| .bhp | BHP Survey Tool Data |
| .bhs | Rise Of Nations Script |
| .bhx | BinHex Compressed File ASCII Archive |
| .bi | Microsoft Visual Basic For DOS Include |
| .bi? | LoseThos Binary Executable |
| .bib | BibTeX Document Format |
| .bibtex | BibTeX Document |
| .bic | Civilization III Game Scenario Format |
| .bid | BidMaker |
| .bidule | Plogue Bidule Sound Layout Format |
| .bie | JBIG Image |
| .bif | TomTom Navigator General Info Format |
| .bifx | Get Backup Project |
| .big | Electronic Arts Game Resource Package Format |
| .bik | BINK Video Format |
| .bikey | Bohemia Interactive Key |
| .bil | ArcView Band Interleaved By Line Image Format |
| .bim | Bytessence InstallMaker Project Format |
| .bimd | Blue Ink Meta-data Export |
| .bimx | ArchiCAD BIMx 3D Scene |
| .bin | CD/DVD Binary Image Format |
| .bin3 | LabVIEW Data |
| .bina | Microsoft Word 5 For Mac Document |
| .binarycookies | Safari Browser Cookies Package |
| .binui | Call Of Juarez Game Menu |
| .bio | OS/2 BIOS Format |
| .bioexcess | MyWinLocker Protected |
| .bionix | Bionix Wallpaper List Format |
| .biot | BiotSavart Magnetic Design |
| .bip | Character Studio Biped Format |
| .biq | Civilization 3 Scenario Format |
| .bit | Xilinx Integrated Software Environment Bitstream Format |
| .bitcfg | Passmark Configuration |
| .bitmap | X Window System Bitmap Image |
| .bitpim | BitPim Configuration Format |
| .bix | Civilization III Scenario Format |
| .biz | Print Shop Business Card Format |
| .bizdocument | Actuate BusinessReport Studio Document |
| .bjf | NTI Backup Now Related |
| .bjk | Blaise |
| .bjo | Instrument Tablature Format |
| .bk | Adobe FrameMaker Book Format |
| .bk! | Corel WordPerfect Document Backup |
| .bk0 | Aspen HYSYS Backup |
| .bk1 | Autodesk AutoCAD Backup Format |
| .bk2 | Windows Indexing Service Data Format |
| .bk3 | Corel WordPerfect Document Backup |
| .bk4 | Corel WordPerfect Document Backup |
| .bk5 | Corel WordPerfect Document Backup |
| .bk6 | Corel WordPerfect Document Backup |
| .bk7 | Corel WordPerfect Document Backup |
| .bk8 | Corel WordPerfect Document Backup |
| .bk9 | Corel WordPerfect Document Backup |
| .bkb | VariCAD Drawing |
| .bkc | Backup4all Catalog Format |
| .bkd | Book Library Local Dos Exploit |
| .bkf | Microsoft Backup Format |
| .bkg | UWXAFS Project Binary Format Data |
| .bki | IBM BookManager Backup Index |
| .bkk | BookBuddi EBook Format |
| .bkmk | Yummy FTP Bookmark Format |
| .bko | Wisco Backup Outlook Backup |
| .bkp | Backup Plus Backup Format |
| .bkr | ReplaceEm File Set |
| .bks | Microsoft Works Spreadsheet Document Backup Format |
| .bku | Timeslips Backup |
| .bkup | Backup Plus Backup Format |
| .bkw | FontEdit Image |
| .bky | Bookkey Bookmark/keyword Data |
| .bkz | FileFort Backup |
| .bla | Adobe Black Colour Separation |
| .blackhawkstriker2 | Blackhawk Striker 2 Saved Game |
| .blackhawkstriker2savedgame | Blackhawk Striker 2 Saved Game |
| .blasterball2drm3savedgame | Blasterball 2 Save Game |
| .blasterball3savedgame | Blasterball 3 Save Game Format |
| .blb | Blob Format |
| .bld | MegaPaint Picture Image Format |
| .blend | Blender 3D Data Format |
| .blend1 | Blender Backup Format |
| .blend2 | Blender Document Backup Format |
| .blf | Microsoft Windows Vista And Windows 7 Registry Format |
| .blg | Microsoft Windows Binary Performance Log Format |
| .bli | Thomson Speedtouch Series WLAN Router Firmware Format |
| .blight | Mario Kart Mod Effect |
| .blk | AutoCAD Block Template Format |
| .blkrt | Block Artist Image Format |
| .bll | Borland Delphi Localization Information |
| .blm | Eurolink Comma Separated Value |
| .bln | Golden Software Blanking File Format |
| .blob | Steam Client Registry Format |
| .blockplt | LEGO MINDSTORMS NXT Palette Format |
| .blogthis | Microsoft Windows Writer BlogThis Data Format |
| .blp | Blizzard Game Texture Format |
| .bls | Blockland Saved Game |
| .blt | AIM AOL Instant Messenger Saved Buddy List |
| .blu | FileMaker Pro Runtime Extension Format |
| .blue | EVE Online Texture |
| .bluebutton | VA Blue Button Text |
| .blv | Might And Magic 6/7 Dungeon Level Geometry |
| .blw | Adobe Photoshop Black And White Presets Format |
| .blx | Magellan MapSend Map Data |
| .bly | FIFA World Cup Game Data Fe Art Load Game |
| .blz | Nokia N-Gage Game Format |
| .bm | X Windows System Bitmap Image |
| .bm2 | Subspace/Continuum Bitmap Graphic Format |
| .bm3 | Sony Ericsson Backup Format |
| .bma | Compressed Archive |
| .bmb | Pro/ENGINEER Temporary |
| .bmc | Microsoft Terminal Server Client Bitmap Cache Format |
| .bmd | Nintendo GameCube 3D Model Format |
| .bmd5 | BookmarkingDaemon |
| .bme | Konami Beatmania Music Simulator Format |
| .bmf | Corel Gallery Binary Material Format |
| .bmg | Mario Kart Wii Message Format |
| .bmi | 3D Studio Max Plugin |
| .bmk | Bookmark Format |
| .bml | Bean Markup Language Format |
| .bmm | Tacmi Pixia Palette |
| .bmml | Balsamiq Mockups Graphic |
| .bmo | SIMATIC WinCC Script |
| .bmp | Standard Windows Bitmap Image (also OS/2) |
| .bmp24 | Bitmap Graphic |
| .bmpenx | Encrypted BMP |
| .bmq | Re-Volt Texture |
| .bms | Beatmania Music Simulator Format |
| .bmt | Alpha Five Image Library |
| .bmu | BioWare Music Unit |
| .bmw | W32/Liji-A Virus |
| .bmx | Siemens Mobile Phone Animation Format |
| .bmz | Compressed Bitmap Format |
| .bn4 | Yamaha DX100 Voice |
| .bna | Atlas Boundary Format |
| .bnc | Bojanov Encryptor Encrypted |
| .bnd | Neighbours From Hell Game Archive |
| .bndl | Bundle File Format |
| .bnf | IBM Voice Type Languages Map |
| .bng | Bingo Maker Bingo Data Template Format |
| .bnhq | BinHex Archive |
| .bni | Blizzard Battle.Net Icon |
| .bnk | Test Drive Unlimited Game Data Format |
| .bnl | MicroSim PCBoard Netlist |
| .bnp | Sony HD Camera System Format |
| .bnr | Nintento Wii Homebrew |
| .bns | Portal Script Format |
| .bnt | Entropia Universe Game Archive |
| .bny | Binary Ll Format |
| .bnz | Bingo Maker Bingo Template Or Bingo List Update Format |
| .bob | BOB Raytracer Bitmap Image |
| .bobo | ClarisWorks |
| .bobthebuildersavedgame | Bob The Builder: Can Do Zoo Save Game |
| .boc | E-Press EasyWord Big Document Format |
| .bochsrc | Bochs Configuration |
| .bod | X3 Reunion Ship |
| .boe | Microsoft Outlook Express Backup |
| .bof | IBM Voice Type Languages Tasks Enroll |
| .boh | Europa Universallis 2 Game Data |
| .bok | TestGen Test Bank Format |
| .bol | Mario Kart Course Setup |
| .bom | Apple Mac OS X Bill Of Materials Format |
| .bonds | Ribbons Bonds |
| .bonk | Bonk Audio Format |
| .boo | Microsoft Booasm.arc Encoded File Archive |
| .book | Adobe FrameMaker Book Format |
| .bookexport | Booksmart Export Format |
| .booktemplate | IBooks Author Book Template Format |
| .bookwormdeluxesavedgame | Bookworm Deluxe Saved Game |
| .boot | InstallShield Format |
| .bootefisignature | Bootefisignature Mac OS X System |
| .bootskin | Microsoft Windows Boot Skin |
| .bootstrap | Adobe HTTP Dynamic Streaming Bootstrap |
| .borland | Borland C Makefile |
| .bos | Fallout Tactics Game Archive |
| .bot | Robot Arena Game |
| .box | FoxMail E-mail Box |
| .box3d | Box Shot 3D Project |
| .boxer | Boxer For Mac Game Archive |
| .boz | Bzip Compressed Archive |
| .bp | DataFlex Business Process Object |
| .bp0 | SmartWare Backup Project |
| .bp1 | Smartware Backup Document |
| .bp2 | Autodesk AutoCAD Batch Plot Format |
| .bp3 | Autedesk AutoCAD Batch Plot Format |
| .bp4 | SmartWare Backup Project |
| .bpa | StorageSync Backup Archive Format |
| .bpb | PowerDesigner Business Process Backup Format |
| .bpc | BuildPro |
| .bpd | Pscript Binary PostScript Printer Description Format |
| .bpdx | Adobe Acrobat Catalog Batch PDX Format |
| .bpf | BatchPhoto Profile Format |
| .bpg | Delphi Project Group Format |
| .bpi | IBM Voice Type Languages New User |
| .bpj | Boxsim Simulation |
| .bpk | Nero SecurDisc Public Key Format |
| .bpkey | Blender Publisher License Key |
| .bpl | Delphi Packed Library Format |
| .bpm | Battle Planner Module Format |
| .bpmc | Bizagi Process Modeler |
| .bpmn | Avantage Template |
| .bpn | ArchiCAD Backup Format |
| .bpnueb | Payame Noor University (PNU) E-book Format |
| .bpo | DataFlex Business Process Object |
| .bpp | Clarion Backup Application |
| .bpr | Borland C++ Builder XML Project Format |
| .bps | Microsoft Works Document Backup Format |
| .bpsd | Backup Plus |
| .bpt | CorelDRAW Bitmap Master |
| .bpv | BallPark Business Valuation Valuation Scenario |
| .bpw | ArcView World File For Bip Or Bmp Images |
| .bpx | Truevision TarGA Bitmap Image |
| .bpz | Easy Blue Print Library |
| .bqf | Backdoor.Win32.Ciadoor.bqf Trojan |
| .bqw | ArcView World |
| .bqy | BrioQuery Database Format |
| .br | Omnis Data |
| .br1 | Total Commander Cached Button Bar Icons |
| .br2 | Total Commander Cached Button Bar Icons |
| .br3 | Bryce 3D Scene Format |
| .br4 | Bryce 4 Scene Format |
| .br5 | Bryce 5 Scene Format |
| .br6 | Bryce 6 Scene Format |
| .br7 | Bryce 7 Scene Format |
| .bra | Linux |
| .bragg | Bragg Profile |
| .brain | PersonalBrain Mind Map Format |
| .brasd | Mario Kart Mod |
| .brb | Bryce Object Export |
| .brc | Bryce 2 Scene |
| .brd | EAGLE Circuit Board Format |
| .bre | Breuckmann Scanner |
| .breff | Mario Kart Wii Animated Graphic |
| .breft | Mario Kart Wii Animated Graphic |
| .brep | 3D Model |
| .brew | Homebrew |
| .brf | Braille Format |
| .brfnt | Mario Kart Wii Font |
| .brg | Age Of Mythology 3D Game Model Format |
| .brh | Baraha |
| .bri | Bryce Plug-in Format |
| .bridgecache | Adobe Bridge Cache |
| .BridgeCacheT | Adobe Bridge Cache |
| .bridgelabelsandratings | Adobe Bridge |
| .BridgeSort | Adobe Bridge Cabinet |
| .bridgesupport | Bridgesupport Mac OS X File Extension |
| .brk | Brooktrout Fax Format |
| .brlcad | BRL-CAD 3D |
| .brlyt | Nintendo Wii Texture Settings Format |
| .brm | Bryce Plug-in Format |
| .brn | BrainStorm Data Format |
| .bro | Tree Professional Broadleaf Creator Format |
| .broguesave | Brogue Saved Game |
| .browser | ASP.NET Browser Definition Format |
| .brp | Tree Professional Broadleaf Creator Image |
| .brpx | E-sword Bible Reading Plan |
| .brres | Wii BRRES Resource Package |
| .brs | Adobe RoboHelp Browse Sequence Format |
| .brsar | Audio Format |
| .brstm | Audio Format |
| .brt | Booria Carpet Designer Robotuft Project |
| .brtex | Wii BRTEX Texture |
| .bru | Brutus Restore |
| .brv | BraveViewer Thumbnail Cache |
| .brw | PointCentral Financial Institutions Loan Format |
| .brx | BREW MP Application Resource Format |
| .bry2 | Bryce 2 |
| .bs | Printfox/Pagefox Image Format |
| .bs1 | VirtualBus Format |
| .bs2 | BASIC Stamp 2 Code Format |
| .bs4 | Mikogo Session Video Recording Format |
| .bs7 | Windows 7 Boot Updater Boot Animation Format |
| .bsa | Bethesda Softworks Archive Format |
| .bsave | Quickbasic BLOAD/BSAVE Format |
| .bsb | MapInfo Sea Chart Format |
| .bsc | Microsoft Visual Studio Visual C++ Source Browser Information Format |
| .bscs | Balanced Scorecard Designer |
| .bsct | Balanced Scorecard Designer Strategy |
| .bsd | BSDL Format |
| .bsdf | ZEMAX Scattering Distribution Data |
| .bsdiff | Cygwin |
| .bsdl | Boundary Scan Description Language Format |
| .bse | CRiSP Harvest |
| .bsf | AVC Blu-ray Video Format |
| .bsh | BeanShell Script Format |
| .bsi | Microsoft SharePoint Server 2007 Temporary |
| .bsk | Bryce 4 Format |
| .bsl | BSPlayer Configuration |
| .bsm | Bioshock Map |
| .bsmx | BeerSmith |
| .bsmz | Compressed BSML |
| .bsn | Autodesk TR-55 Detention Basin Storage Data |
| .bson | BSON Binary JSON |
| .bsp | Quake 2 Map Format |
| .bspr | Need For Speed SHIFT Track Map |
| .bsproj | Banned Story Project |
| .bsq | BinScii Binary Archivne |
| .bsr | Bacula Restore |
| .bss | Resident Evil Background Images Format |
| .bst | BiblioTex Format |
| .bsv | Bluespec System Verilog |
| .bsw | Business Scorecard Manager Workspace |
| .bswx | Microsoft Office PerformancePoint Server Database |
| .bsx | PBASIC Preprocessor Output |
| .bsy | VTrain Learning Cardfile |
| .bsz | BSplayer Compressed Skin |
| .bt | VTBuilder Binary Terrain Format |
| .bt! | BitSpirit Incomplete Download Format |
| .bt0 | Band-in-a-Box Temporary |
| .bt1 | Battery Analyzer Test |
| .bt2 | Batch Barcode Maker |
| .bt3 | Control Runner Button Configuration |
| .bt5 | ERP5 Business Template |
| .btapp | UTorrent Application Format |
| .btd | Business-in-a-Box Document Format |
| .btf | NationsBank Check Images |
| .btg | FlightGear Scenery |
| .bth | Bathy Recorder Data |
| .bti | Nintendo Texture Format |
| .btif | NationsBank Check Image Format |
| .btinstall | BitTorrent Installation Format |
| .btk | CLwin Tekton Database |
| .btkey | BitTorrent License Key |
| .btl | SolidWorks Sheet Metal Bend Table |
| .btm | Microsoft BizTalk Map Format |
| .btn | Just Buttons Animated Bitmap Image Format |
| .bto | Bryce Tree Format |
| .btoa | Binary-to-ASCII File Format |
| .btr | Btrieve Database Format |
| .btree | Apple Mac OS HFS+ B-tree |
| .bts | Creative Digital Blaster Digital VCR |
| .btsearch | BitTorrent Search Engine Specification Format |
| .btskin | µTorrent Skin |
| .btst | Norton SystemWorks Info |
| .btt | ICQ Find Users |
| .btu | Diablo BTU Calculator |
| .btw | BarTender Barcode Label Format |
| .btwsendto | Microsoft Windows Bluetooth Related |
| .btx | InMagic Database Term/word Index |
| .bty | Railroad Tycoon 3 Building |
| .bu | Pegasus Mail Temporary |
| .bub | Photobubble |
| .buc | Adobe Photoshop Elements Backup |
| .bud | Pscript Binary PostScript Printer Description Format |
| .buf | Buffer Format |
| .bufferedimage | Java Class |
| .bugsense | BugSense |
| .build | NAnt Build Tool |
| .buildalot2savedgame | Build-a-lot 2 Save Game |
| .buildalot3savedgame | Build-a-lot 3 Saved Game |
| .builder | Builder Script |
| .buildpath | Eclipse XML Build Path Format |
| .buj | Personal Backup Saved Task |
| .bul | Bullseye Data Format |
| .bum | Poser Bump Files Image Format |
| .bun | CakeWalk Audio Bundle Format |
| .bundle | Mac OS X Application Extension |
| .bundledmesh | Battlefield Bundled Mesh |
| .bup | Backup Of DVD Info Format |
| .bur | BuRg3r Source Code Format |
| .burn | Burn For Mac OS X Document |
| .BurnoutParadiseSave | Burnout Paradise Saved Profile |
| .burntheme | Burn For Mac OS X Theme Document |
| .bus | VirtualBus Bus Route Settings Format |
| .bv1 | Corel WordPerfect Overflow |
| .bv2 | Corel WordPerfect Overflow |
| .bv3 | Corel WordPerfect Overflow |
| .bv4 | Corel WordPerfect Overflow |
| .bv5 | Corel WordPerfect Overflow |
| .bv6 | Corel WordPerfect Overflow |
| .bv7 | Corel WordPerfect Overflow |
| .bv8 | Corel WordPerfect Overflow |
| .bv9 | Corel WordPerfect Overflow |
| .bvc | IBM Voice Type Languages Newuser |
| .bvd | BitDefender Vault Format |
| .bvh | Biovision Hierarchy Animation Format |
| .bvi | IBM Voice Type Languages Newuser |
| .bvl | Micrografx Picture Publisher 8 Textures |
| .bvp | Bluevoda Website Builder Format |
| .bvr | Blue Iris Video Format |
| .bvs | BVS Solitaire Collection |
| .bvw | SmartWare Backup Standard View |
| .bvx | OptiTune Install Package |
| .bvxd | OptiTune Manifest |
| .bw | Silicon Graphics Image |
| .bw1 | FMEA Database |
| .bwa | BlindWrite BWA Builder Physical CD Characteristics Format |
| .bwc | BeadWizard Color Palette |
| .bwd | Colin McRae Rally 2 Car Description |
| .bwe | Black And White 2 Environment Data |
| .bwf | Broadcast Wave File Format |
| .bwg | BrainWave Generator Format |
| .bwi | BlindWrite CD/DVD Image Format |
| .bwm | Blaise |
| .bwp | BuRg3r Web Page |
| .bws | BlindWrite Subchannel Data Format |
| .bwt | Blindwrite Control Format |
| .bwu | Blindwrite CD Copier |
| .bww | Bagpipe Music Writer Music Notation Format |
| .bwz | WinImage Batch Configuration |
| .bx | Opera |
| .bxb | BasicX Compiled Project Bytecode |
| .bxi | Blaise |
| .bxl | Accelerated Designs PCB Library Format |
| .bxm | BasicX-24 Basic Express Compiler Map |
| .bxml | Bean XML |
| .bxp | BasicX-24 Basic Express Compiler Module List |
| .bxrc | Configuration |
| .bxu | PictureGear Studio |
| .bxx | BlaxxunContact Format |
| .bxy | NuFX Archive Within A Binary II Envelope |
| .by | PSpice |
| .byu | Movie.BYU Geometry Format |
| .bz | BZIP Compressed File Archive |
| .bz1 | WinTOTAL Automatic Backup |
| .bz2 | Bzip2 Compressed File Archive |
| .bza | Bzip2 Compressed File Archive |
| .bzabw | AbiWord Bzip2 Compressed Document Format |
| .bzip | Bzip Compressed Archive |
| .bzip2 | BZIP Compressed Archive Format |
| .bzm | Business Map |
| .bzn | Star Trek Armada Map |
| .bzp2 | BZIP2 Archive |
| .bzs | BlueZone Script |
| .bzw | BZFlag Map Format |
| .bzz | BuzzBundle Project |
File extensions are not normally displayed to users. To change this, go to Control Panel, select Appearance and Personalization and Folder Options. Next, select the View and find the option "Hide extensions for known file types". The option should be deselected (cleared) and confirmed with OK.
