O, FILE EXTENSIONS STARTING FROM ALPHABET 'O'

O
Ext.	Description	Used by
O$$	Outfile	Sprint
O	Object file	UNIX - Atari - GCC
O01	Typhoon vOice file	AWAVE
OAZ	Fax	NetFax Manager
OB	Object cut/paste file	IBM LinkWay
OBD	Microsoft Office Binder	MSOffice
OBJ	Compiled machine language code
OBJ	Object code	Intel Relocatable Object Module
OBJ	Wavefront Object
OBJF	Data	Triangle strips object
OBR	Object browser data file	Borland C++
OBS	Script	ObjectScript
OBT	Microsoft Office Binder Template	MSOffice
OBV	Visual interface	ObjectScript
OBZ	Microsoft Office Binder Wizard	MSOffice
OCF	Object Craft File	Object Craft
OCD	OCAD Map File	OCAD
OCR	Incoming fax transcribed to text	FAXGrapper
OCT	Musical file	Pctalizer
OCX	New Custom Control's format in VB 4.0	Visual Basic
OCX	OLE custom control
ODB	OpenDocument database	OpenOffice.org Base
ODF	OpenDocument formula	OpenOffice.org Math
ODG	OpenDocument drawing	OpenOffice.org Draw
ODIF	Open Document Interchange Format
ODL	Object Description Language
ODL	Type library source	Visual C++
ODM	OpenDocument master document	OpenOffice.org Writer
ODP	OpenDocument presentation	OpenOffice.org Impress
ODS	OpenDocument spreadsheet	OpenOffice.org Calc
ODT	OpenDocument text document	OpenOffice.org Writer
OFD	Form definition	ObjectView
OFF	Object File Format vector graphics file
OFF	Object File Format vector graphics
OFM	PostScript font description file
OFN	Microsoft Office documents	Microsoft Office
OGG	Ogg multimedia container format
OHB	Source	On Hand Basic
OHS	Outbound History	Bink/+
OIF	QuickBase file format
OKT	Music (8 channels)	Oktalyzer
OKT	Music format	Oktalyzer
OLB	Object library	VAX
OLD	Backup file
OLI	Text file	Olivetti
OLSR	Configuration file	olsrd
OMA	Audio file	Labelgate CD 2, MAGIQLIP2
OOF	Data	Outrage 3D Object Format (Descent)
OOG	Data	WEBOOGL 3D object
OOM	Swap file	Shroom
OPJ	Origin Project File	Origin version 4.1 and later
OPN	Active options	Exact
OPT	Options	name used by many programs for configuration information
OPT	Delphi project options	Borland Delphi
OPT	Optimize support file	QEMM
OPW	Organization chart	Org Plus for Windows
OPX	Inactive options	Exact
ORA	Parameter file	Oracle
ORC	Orchestra MIDI file	CSound
ORG	Calendar file	Lotus Organizer
ORG	Older Origin Project	Origin versions 4 or earlier
OTG	OpenDocument drawing template	OpenOffice.org Draw
OTB	Over-the-air bitmap graphics
OTF	Subtitle font information for media content	Media players / software which support PGS subtitling
OTH	OpenDocument HTML document template	OpenOffice.org
OTL	Outline font description	Z-Soft Type Foundry
OTL	Ventura Publisher's Type Foundry Outline Editor format
OTP	OpenDocument presentation template	OpenOffice.org Impress
OTS	OpenDocument spreadsheet template	OpenOffice.org Math
OTT	OpenDocument text document template	OpenOffice.org Writer
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)	TomTom Point of Interest
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)
OXT	OpenOffice.org extension	OpenOffice.org