| File extension |
File description |
Developer/Producer |
| .o |
Compiled Object File |
N/A |
| .oab |
Offline Address Book |
N/A |
| .oam |
Adobe Edge Animate Widget File |
Adobe Systems |
| .oar |
OpenSimulator Archive |
N/A |
| .ob! |
Orbit Downloader Incomplete Download |
Orbit Downloader |
| .obb |
Android Opaque Binary Blob File |
Google |
| .obd |
Office Binder Document |
Microsoft |
| .obi |
Outlook RSS Subscription File |
Microsoft |
| .obj |
Wavefront 3D Object File |
Wavefront Technologies |
| .obml |
Opera Mini Saved Web Page |
Opera Software |
| .obp |
Bryce Object File |
DAZ Productions |
| .obt |
Openbox Theme File |
Openbox |
| .obw |
Superior Drummer Sounds File |
Toontrack |
| .obz |
Compressed 3D Object File |
Smith Micro |
| .oc3 |
openCanvas 3 Event File |
Portalgraphics |
| .oc4 |
openCanvas 4 Event File |
Portalgraphics |
| .oc5 |
openCanvas 5 Event File |
Portalgraphics |
| .oca |
Custom Control Library Type File |
Microsoft |
| .occ |
Oceanic DataPool File |
Oceanic Consulting Corporation |
| .ocd |
OCAD Map File |
OCAD |
| .oce |
Open Catalog Extension Connection File |
Oracle |
| .oci |
openCanvas Image |
Portalgraphics |
| .ocr |
FAXGrapper Fax Text File |
Nuance Communications |
| .oct |
Radiance Octree File |
Radiance |
| .octest |
Xcode Objective-C Unit Test Bundle |
Apple |
| .ocx |
ActiveX Control |
Microsoft |
| .od |
Mascopt Graph Request File |
INRIA/UNSA |
| .odb |
OpenDocument Database |
OASIS |
| .odc |
Office Data Connection File |
Microsoft |
| .odf |
OpenDocument Formula |
Oracle |
| .odg |
OpenDocument Graphic File |
OASIS |
| .odi |
OpenDocument Image |
OASIS |
| .odif |
Open Document Interchange Format |
ITU-T |
| .odl |
Object Description Language File |
Microsoft |
| .odm |
OverDrive Media File |
OverDrive |
| .odo |
Online Operating System Write Document |
iCUBE Network Solutions |
| .odp |
OpenDocument Presentation |
Oracle |
| .ods |
OpenDocument Spreadsheet |
Oracle |
| .odt |
OpenDocument Text Document |
Oracle |
| .odx |
BizTalk Server Orchestration File |
Microsoft |
| .oeaccount |
Windows Mail Account File |
Microsoft |
| .oeb |
Outlook Express Backup Wizard File |
QSX |
| .oem |
OEM Setup File |
Microsoft |
| .oex |
Opera Extension |
Opera Software |
| .ofc |
Open Financial Connectivity File |
Microsoft |
| .off |
Object File Format |
N/A |
| .ofl |
Ots File List |
Ots Labs |
| .ofm |
Melco Embroidery File |
Melco |
| .ofr |
OptimFROG Audio File |
OptimFROG |
| .oft |
Outlook File Template |
Microsoft |
| .ofx |
Open Financial Exchange File |
N/A |
| .oga |
Ogg Vorbis Audio File |
Xiph.Org |
| .ogf |
S.T.A.L.K.E.R. Model File |
GSC Game World |
| .ogg |
Ogg Vorbis Audio File |
Xiph.Org |
| .ogm |
Ogg Media File |
N/A |
| .ognc |
Dynamic Web Page |
N/A |
| .ogs |
Origons Movie Data File |
Origons |
| .ogv |
Ogg Video File |
Xiph.Org |
| .ogx |
Ogg Vorbis Multiplexed Media File |
Xiph.Org |
| .ogz |
Cube 2 Map File |
Wouter van Oortmerssen |
| .okt |
Oktalyzer Module |
N/A |
| .ola |
Online Access File |
N/A |
| .olb |
OLE Object Library |
Microsoft |
| .old |
Backup File |
N/A |
| .olk |
Outlook Address Book File |
Microsoft |
| .olk14category |
Outlook Category File |
Microsoft |
| .olk14contact |
Outlook Contact File |
Microsoft |
| .olk14event |
Outlook Calendar Event File |
Microsoft |
| .olk14group |
Outlook Group File |
Microsoft |
| .olk14mailaccount |
Outlook Mail Account File |
Microsoft |
| .olk14message |
Outlook Message File |
Microsoft |
| .olk14msgsource |
Outlook Email Message Data File |
Microsoft |
| .olk14note |
Outlook Note File |
Microsoft |
| .olk14pref |
Outlook Preferences File |
Microsoft |
| .olk14signature |
Outlook Signature File |
Microsoft |
| .olk14task |
Outlook Task File |
Microsoft |
| .olm |
Mac Outlook Database File |
Microsoft |
| .olt |
Orbit Downloads List |
Orbit Downloader |
| .oma |
Sony OpenMG Music File |
Sony |
| .omcs |
Office Manager Access File |
Krekeler |
| .omf |
Open Media Framework File |
Avid Technology |
| .omg |
OpenMG Audio File |
Sony |
| .omo |
OMake Object File |
OMake |
| .omod |
Oblivion Mod Archive |
N/A |
| .omp |
Office Manager Document Archive |
Krekeler |
| .omx |
OtsAV Media Library Information File |
Ots Labs |
| .ond |
Lotus Notes Encapsulated Memo File |
IBM |
| .one |
OneNote Document |
Microsoft |
| .onepkg |
Microsoft OneNote Package File |
Microsoft |
| .onetoc2 |
Microsoft OneNote Table of Contents File |
Microsoft |
| .ont |
theWord Bible Text Module |
theWord Bible Software |
| .ontx |
theWord Encrypted Bible Text Module |
theWord Bible Software |
| .oo3 |
OmniOutliner 3 File |
The Omni Group |
| .ook |
Arachne Batch Script |
Arachne |
| .opd |
OmniPage Document |
Nuance Communications |
| .opdownload |
Opera Partially Downloaded File |
Opera Software |
| .openbsd |
OpenBSD Readme File |
N/A |
| .opf |
Open Packaging Format File |
IDPF |
| .opj |
OrCAD Project File |
Cadence Design Systems |
| .oplc |
Nokia Operator Logo File |
Nokia |
| .opml |
Outline Processor Markup Language File |
N/A |
| .ops |
Office Profile Settings File |
Microsoft |
| .opt |
Options File |
N/A |
| .options |
SE-SOFT Configuration File |
SE-SOFT |
| .opts |
Linux Configuration Options File |
N/A |
| .opus |
Opus Audio File |
Xiph.Org |
| .opx |
OrgPlus Org Chart |
Insperity Business Services |
| .oqy |
Excel OLAP Query File |
Microsoft |
| .or2 |
Lotus Organizer 2 File |
IBM |
| .or3 |
IBM Lotus Organizer 97 File |
IBM |
| .or4 |
IBM Lotus Organizer 97 GS File |
IBM |
| .or5 |
Lotus Organizer 5 File |
IBM |
| .or6 |
Lotus Organizer 6 File |
IBM |
| .ora |
Oracle Database Configuration File |
Oracle |
| .orc |
Voyetra Digital Orchestrator File |
Voyetra |
| .orderedtest |
Visual Studio Ordered Test File |
Microsoft |
| .ore |
Ore Executable File |
crait |
| .orf |
Olympus RAW File |
Olympus |
| .org |
Lotus Organizer File |
N/A |
| .ori |
Original File |
N/A |
| .orig |
Original File |
N/A |
| .ort |
Rich Text Editor Document |
IBM |
| .orv |
Oracom Video File |
Oracom |
| .orx |
RadiantOne VDS Database Schema |
Radiant Logic |
| .os |
ObjectScript Source File |
ObjectScript |
| .osax |
AppleScript Scripting Addition |
Apple |
| .osb |
OpenStreetMap Binary Map File |
Merkaartor |
| .osc |
OpenStreetMap Change File |
OpenStreetMap |
| .osdx |
Search Connector Description File |
Microsoft |
| .osk |
Osu! Skin File |
peppy |
| .osm |
OpenStreetMap Map File |
OpenStreetMap |
| .osp |
OpenShot Project File |
Jonathan Thomas |
| .osr |
Osu! Replay File |
peppy |
| .oss |
Microsoft Outlook Saved Search File |
Microsoft |
| .ost |
Outlook Offline Folder File |
Microsoft |
| .osu |
Osu! Script |
peppy |
| .osx |
PowerPC Executable File |
N/A |
| .osz |
Osu! Beatmap File |
peppy |
| .ot |
theWord Old Testament Text Module |
theWord Bible Software |
| .ota |
OTA Bitmap Image |
Nokia |
| .otb |
Nokia Over The Air Bitmap Image |
Nokia |
| .otc |
OpenDocument Chart Template |
OASIS |
| .otf |
OpenType Font |
N/A |
| .otg |
OpenDocument Graphic Template |
OASIS |
| .oth |
OpenDocument HTML Template |
OASIS |
| .oti |
OpenDocument Image Template |
OASIS |
| .otl |
NoteTab Outline File |
Fookes Software |
| .otln |
Opal Outline File |
A Sharp |
| .otm |
Outlook Macro File |
Microsoft |
| .otp |
OpenDocument Presentation Template |
OASIS |
| .otrkey |
OnlineTvRecorder Encoded Video File |
OnlineTvRecorder.com |
| .ots |
OpenDocument Spreadsheet Template |
OASIS |
| .ott |
OpenDocument Document Template |
OASIS |
| .otx |
theWord Encrypted Old Testament Text Module |
theWord Bible Software |
| .otz |
OpenLP Theme File |
OpenLP |
| .out |
Output File |
N/A |
| .ov2 |
TomTom Points of Interest Database |
TomTom |
| .ova |
Open Virtual Appliance |
VMware |
| .ove |
Overture Musical Score |
GenieSoft |
| .ovf |
Open Virtualization File |
VMware |
| .ovl |
Rollercoaster Tycoon 3 Data File |
Atari |
| .ovp |
The Overlay Maker Package File |
The Overlay Maker |
| .ovpn |
OpenVPN Configuration File |
OpenVPN Technologies |
| .ovr |
The Overlay Maker Overlay File |
The Overlay Maker |
| .ovw |
Logic Pro Overview File |
Apple |
| .ow |
Free Pascal 1.0.x Object File |
Free Pascal |
| .owc |
OutWit Catch Database |
OutWit Technologies |
| .owg |
OutWit Gear Database |
OutWit Technologies |
| .owl |
OWL Source Code File |
N/A |
| .owm |
OutWit XML Mashup File |
OutWit Technologies |
| .oxps |
OpenXPS File |
Microsoft |
| .oxt |
Apache OpenOffice Extension |
Sun Microsystems |
| .oxygene |
Oxygene Project File |
RemObjects |
| .oyx |
Approach Alternate Database Index |
N/A |
| .oz |
Opera Job Management Compressed File |
Opera Company |
