List of file formats beginning with O

• .O - Object file (unix - Atari - GCC)
• .O$$ - Outfile (Sprint)
• .OAZ - Fax (NetFax Manager)
• .OB - Object cut/paste file (IBM LinkWay)
• .OBD - MS Office Binder
• .OBJ - Object code (Intel Recolatable Object Module)
• .OBR - Object browser data file (Borland C++)
• .OBS - Script (ObjectScript)
• .OBV - Visual interface (ObjectScript)
• .OCA - Control Typelib Cache
• .OCF - Object Craft File (Object Craft)
• .OCM - AOL Advertising Control filesInternet Odyssey 2 Update
• .OCP - Advanced Art Studio; Offline Commander Project file
• .OCR - Incoming fax transcribed to text (FAXGrapper) - Find out how eFax delivers faxes right to your email inbox. Try it free - instant activation.
• .OCT - Radiance Octree Format
• .OCX - OLE custom control
• .ODF - Open Document Interchange; BattleZone Cartographers Guild file; Star Trek Armada Ship/Structure Infomation
• .ODL - Type library source (Visual C++)
• .OEB - Outlook Express Backup Wizard
• .OFC - Open Financial Connectivity file
• .OFD - Form definition (ObjectView)
• .OFF - Object File Format vector graphics
• .OFM - Adobe font
• .OFT - MS Outlook Item Template
• .OFX - Olicom Fax Open Financial Exchange file
• .OGG - Ogg Vorbis Codec Compressed WAV file
• .OGM - Ogg Vorbis Compressed Video file
• .OKT - Music (Oktalizer)
• .OLB - Object library (VAX)
• .OLD - Backup file

• .OLE - Object Linking and Embedding Object
• .OLI - Text file (Olivetti)
• .OMG - OpenMG Jukebox
• .OMS - Briggs Softworks Order Maven; Macintosh MP3 Music Format; Omega Downloader Configuration file
• .OND - Lotus Notes-related file
• .OOM - Swap file (Shroom)
• .OPD - Omnipage file - Get 5% OFF OmniPage Professional 17 - Use Promo Code: ervtp2bfh
• .OPF - Flip Album file
• .OPL - Psion Organiser Programming Language Source file
• .OPN - Active options (Exact)
• .OPT - Optimize support file (QEMM)
• .OPW - Organization chart (Org Plus for Windows)
• .OPX - Inactive options (Exact)
• .OR2 - Lotus Organizer 2 file
• .OR3 - Lotus Organizer 97 file
• .OR4 - Lotus Organizer file
• .OR5 - Lotus Organizer file
• .ORA - Parameter file (Oracle)
• .ORG - Calendar file (Lotus Organizer)
• .OSD - Open Software Description file
• .OSS - MS Office Saved Search
• .OST - Microsoft Outlook Offline file
• .OTF - Open Type Format
• .OTL - Outline font description (Z-Soft Type Foundry)
• .OTX - Text file (Olivetti Olitext Plus)
• .OUT - Output file
• .OV1 - Overlay file (part of program to be loaded when needed)
• .OV2 - Overlay file (part of program to be loaded when needed)
• .OVD - Datafile (ObjectVision)
• .OVL - Overlay file (part of program to be loaded when needed)
• .OVR - Overlay file (part of program to be loaded when needed)
• .OVW - Cool Edit Pro Overview File; Cubase .WAV File Image; DIANA Overview File
• .OWS - Web Studio 2 Project file