File extensions that start with the letter "O"

ExtensionDescriptionFile Type
oFree Pascal Object FileDeveloper Files
ob!Orbit Downloader Incomplete DownloadMisc Files
obj3D Objects File3D Files
obml15Opera Mini Saved Web PageWeb Files
ocxActiveX Control FileDeveloper Files
odgOpenDocument Graphic FileGraphic Files
odpOpenOffice Presentation FileData Files
odsOpenOffice Spreadsheet FileData Files
odtOpen Office Document FileText Files
oemTextSetup OEM FileSettings Files
oexOpera Add-on FileWeb Files
ofcOpen Financial Connectivity FileData Files
ofxOpen Financial Exchange FileData Files
oggOgg Vorbis Compressed FileAudio Files
ogmOgg Media FileVideo Files
ogvVideo Container FileVideo Files
oldBackup FileBackup Files
omaOpenMG Music FileAudio Files
omsOrder Maven FileMisc Files
oneOneNote Document FileData Files
ontBible FileMisc Files
opdOptical Path Difference FileData Files
opfOpen Packaging Format FileMisc Files
opmlOutline Processor Markup Language FileDeveloper Files
opsOffice Profile Settings FileSettings Files
optOption FilesSettings Files
orcDigital Orchestrator Pro/Plus Sound FileAudio Files
orgLotus Organizer FileData Files
origGen Original FileMisc Files
originalComponent BBScomp FileWeb Files
ostOutlook Offline FileData Files
outOutput FileData Files
ov2TomTom Point Of Interest FileMisc Files
oveOverture Score FileAudio Files
ovlRollercoaster Tycoon Data FileData Files
ovrMicrosoft Overlay FileSystem Files
oxtOpen Office Extension FileMisc Files