O File Extensions

File Extension File Type Popularity
.O Compiled Object File 4.6
.OAB Offline Address Book 4
.OAM Adobe Edge Animate Widget File 4.5
.OAR OpenSimulator Archive 3.5
.OAT Android Optimized Application File 4
.OB! Orbit Downloader Incomplete Download 4.7
.OB2 Oberon-2 Source Code File 3.5
.OBB Android Opaque Binary Blob File 4.4
.OBD Office Binder Document 4
.OBI Outlook RSS Subscription File 4.8
.OBJ Wavefront 3D Object File 4.5
.OBJ Relocatable Object Code 4.4
.OBK Backup File 4.2
.OBML Opera Mini Saved Web Page 4.2
.OBML15 Opera Mini Saved Web Page 4
.OBML16 Opera Mini Saved Web Page 4.5
.OBP Bryce Object File 3.5
.OBT Openbox Theme File 3.5
.OBW Superior Drummer Sounds File 4
.OBZ Compressed 3D Object File 3.5
.OC3 openCanvas 3 Event File 4
.OC4 openCanvas 4 Event File 4
.OC5 openCanvas 5 Event File 4
.OCA Custom Control Library Type File 4.2
.OCC Oceanic DataPool File 3.5
.OCD OCAD Map File 3.8
.OCE Open Catalog Extension Connection File 3.5
.OCI openCanvas Image 4
.OCR Subtitle Workshop OCR Script 4.2
.OCR FAXGrapper Fax Text File 3.5
.OCT Radiance Octree File 4
.OCTEST Xcode Objective-C Unit Test Bundle 4.5
.OCX ActiveX Control 4.5
.OD Mascopt Graph Request File 4.2
.ODB OpenDocument Database 4
.ODB ABAQUS Database 3.8
.ODC Office Data Connection File 4.1
.ODC OpenDocument Chart File 3.8
.ODEX Optimized Dalvik Executable 4
.ODF OpenDocument Formula 4.2
.ODF Battlezone Object Definition File 3.6
.ODF Open Document File 3
.ODG OpenDocument Graphic File 4
.ODI OpenDocument Image 3.2
.ODIF Open Document Interchange Format 3
.ODL Object Description Language File 4
.ODM OpenDocument Master Document 4.2
.ODM OverDrive Media File 4
.ODO Online Operating System Write Document 3.6
.ODP OpenDocument Presentation 4.4
.ODS OpenDocument Spreadsheet 4.2
.ODS Outlook Express 5 Mailbox 3.2
.ODT OpenDocument Text Document 4.2
.ODTTF Obfuscated OpenType Font 4.2
.ODX BizTalk Server Orchestration File 3.5
.OEACCOUNT Windows Mail Account File 4.4
.OEB Outlook Express Backup Wizard File 4
.OEB Open eBook File 3.5
.OEBZIP Zipped Open eBook File 3.5
.OEM OEM Setup File 4.1
.OEM OEMEdit Save File 3.5
.OEX Opera Extension 4.5
.OFC Open Financial Connectivity File 4
.OFF Object File Format 4.5
.OFFICEUI Microsoft Office UI Customization File 3.5
.OFL Ots File List 4
.OFM OmniForm Form 3.5
.OFM Melco Embroidery File 3.5
.OFR OptimFROG Audio File 3.3
.OFR SMS Offer Manager File 3
.OFT Outlook File Template 3.9
.OFX Open Financial Exchange File 4.3
.OGA Ogg Vorbis Audio File 4.2
.OGF S.T.A.L.K.E.R. Model File 4.2
.OGG Ogg Vorbis Audio File 4.4
.OGM Ogg Media File 4.4
.OGNC Dynamic Web Page 4
.OGS Origons Movie Data File 3
.OGV Ogg Video File 4.2
.OGX Ogg Vorbis Multiplexed Media File 4
.OGZ Cube 2 Map File 4.5
.OIV OpenIV Mod Package File 4.6
.OKT Oktalyzer Module 4
.OL Valve Hammer Object Layout File 4.2
.OLA Online Access File 4
.OLB OLE Object Library 4.2
.OLB OrCAD Symbol Library File 3.9
.OLD Backup File 4.4
.OLK Outlook Address Book File 3.8
.OLK14CATEGORY Outlook Category File 3.5
.OLK14CONTACT Outlook Contact File 3.5
.OLK14EVENT Outlook Calendar Event File 3.5
.OLK14GROUP Outlook Group File 3.5
.OLK14MAILACCOUNT Outlook Mail Account File 3.5
.OLK14MESSAGE Outlook Message File 4.3
.OLK14MSGSOURCE Outlook Email Message Data File 4.2
.OLK14NOTE Outlook Note File 3.5
.OLK14PREF Outlook Preferences File 3
.OLK14SIGNATURE Outlook Signature File 3.5
.OLK14TASK Outlook Task File 3
.OLL TrialDirector Object Load List 3.5
.OLM Mac Outlook Database File 4
.OLP Office Live Package 4
.OLT Orbit Downloads List 3.8
.OMA Sony OpenMG Music File 4.3
.OMCS Office Manager Access File 3.5
.OMF Open Media Framework File 4.5
.OMF OMF Interchange Image File 3.6
.OMG Image File 4.7
.OMG OpenMG Audio File 4.5
.OMO OMake Object File 4
.OMOD Oblivion Mod Archive 4
.OMP OpenMind Windows Document 4
.OMP Office Manager Document Archive 4
.OMX OtsAV Media Library Information File 4
.OND Lotus Notes Encapsulated Memo File 3.5
.ONE OneNote Document 4.2
.ONEPKG Microsoft OneNote Package File 4.4
.ONETOC2 Microsoft OneNote Table of Contents File 4.3
.ONT theWord Bible Text Module 4.5
.ONTX theWord Encrypted Bible Text Module 4
.OO3 OmniOutliner 3 File 4.6
.OO3TEMPLATE OmniOutliner Template 3.5
.OOK Arachne Batch Script 3
.OP OpenPAT Report 4
.OP2 Nastran Output File 3.5
.OP4 Nastran Output File 3.5
.OPAL Microsoft Office User Settings File 3.2
.OPAX Microsoft Office User Settings File 4.2
.OPD OmniPage Document 4.2
.OPD Durango Document 3.5
.OPDOWNLOAD Opera Partially Downloaded File 4.5
.OPENBSD OpenBSD Readme File 4
.OPF FlipViewer FlipBook File 4.3
.OPF Open Packaging Format File 4.2
.OPF FlipAlbum File 3.5
.OPJ OrCAD Project File 4.3
.OPLC Nokia Operator Logo File 4
.OPML Outline Processor Markup Language File 4.6
.OPS Office Profile Settings File 4.5
.OPT Options File 4.7
.OPT Opterecenja File 4.3
.OPT AGT Game Data File 4
.OPTIONS SE-SOFT Configuration File 3
.OPTS Linux Configuration Options File 3.2
.OPUS Opus Audio File 4.3
.OPX OrgPlus Org Chart 4.2
.OPX FlipAlbum Photo Album File 3.8
.OQY Excel OLAP Query File 4
.OR2 Lotus Organizer 2 File 3
.OR3 IBM Lotus Organizer 97 File 3
.OR4 IBM Lotus Organizer 97 GS File 3.5
.OR5 Lotus Organizer 5 File 3.8
.OR6 Lotus Organizer 6 File 4
.ORA Oracle Database Configuration File 4
.ORA OpenRaster Image File 3.8
.ORC Voyetra Digital Orchestrator File 3
.ORDEREDTEST Visual Studio Ordered Test File 3.5
.ORE Ore Executable File 3
.ORF Olympus RAW File 4.4
.ORG Lotus Organizer File 4.1
.ORI Original File 4
.ORIG Original File 4.2
.ORT Rich Text Editor Document 3.2
.ORV Oracom Video File 4
.ORX RadiantOne VDS Database Schema 4
.OS ObjectScript Source File 4.2
.OSAX AppleScript Scripting Addition 4.2
.OSB OpenStreetMap Binary Map File 3.8
.OSC OpenStreetMap Change File 4
.OSC Obix Source Code File 3.5
.OSDX Search Connector Description File 4.5
.OSK Osu! Skin File 4.1
.OSM OpenStreetMap Map File 4.2
.OSP OpenShot Project File 4.5
.OSR Osu! Replay File 4.3
.OSS Microsoft Outlook Saved Search File 4
.OST Outlook Offline Folder File 4
.OSU Osu! Script 3.8
.OSX PowerPC Executable File 4
.OSZ Osu! Beatmap File 4.7
.OSZ OpenLP Service File 4
.OT theWord Old Testament Text Module 4
.OTA OTA Bitmap Image 4
.OTB Nokia Over The Air Bitmap Image 4
.OTC OpenDocument Chart Template 3.5
.OTF OpenType Font 4.4
.OTF OpenTuft Tufting Design File 3.5
.OTF OpenDocument Formula Template 3.3
.OTG OpenDocument Graphic Template 4
.OTH OpenDocument HTML Template 4
.OTI OpenDocument Image Template 3.5
.OTL NoteTab Outline File 4
.OTLN Opal Outline File 4
.OTM Outlook Macro File 4
.OTP OpenDocument Presentation Template 4.2
.OTRKEY OnlineTvRecorder Encoded Video File 4
.OTS OpenDocument Spreadsheet Template 4.1
.OTS OtsAV Album File 3.5
.OTT OpenDocument Document Template 4.2
.OTX theWord Encrypted Old Testament Text Module 3.5
.OTZ OpenLP Theme File 3.5
.OUT Compiled Executable File 4
.OUT Output File 4
.OV2 TomTom Points of Interest Database 3.8
.OVA Open Virtual Appliance 4.5
.OVA Octava Musical Score 3.9
.OVE Overture Musical Score 3.8
.OVF Open Virtualization File 4
.OVH OMSI Vehicle Configuration File 4
.OVL Rollercoaster Tycoon 3 Data File 4.1
.OVOLOG ooVoo Log File 3.5
.OVP The Overlay Maker Package File 3.5
.OVPN OpenVPN Configuration File 4.5
.OVR The Overlay Maker Overlay File 4
.OVW Logic Pro Overview File 4
.OVW Cubase WAVE Overview File 3.5
.OW Free Pascal 1.0.x Object File 4
.OWC OutWit Catch Database 3.5
.OWG OutWit Gear Database 3.5
.OWL OWL Source Code File 4.7
.OWM OutWit XML Mashup File 4.3
.OWX OutWit Hub Automator File 4
.OXPS OpenXPS File 4.3
.OXT Apache OpenOffice Extension 4
.OXYGENE Oxygene Project File 3.5
.OYX Approach Alternate Database Index 3.8
.OZ Opera Job Management Compressed File 3.5
.OZB MU Online Image File 4
.OZJ MU Online Image File 4.3
.OZT MU Online Image File 4.2