OMX-OMAX-Make-Tool-Path-File-OMAX-Corporation
OMX-OtsAV-Media-Library-Information-File
OMX-Ots-Media-Library-Header
ON2-on2-encoded-FLV-file
ON-Audio-Utility-Tuningwrench-compressed-file
ON-Cubase-Fonts-Compressed-File-Steinberg
OND-Lotus-Notes-Database-Header
OND-Lotus-Notes-file
OND-Notes-Database-IBM
ONE-docPointer-Visual-ReadMe-file
ONE-EdgeCAM-Licensing-data-file
ONE-Microsoft-OneNote-2007-file
ONEPKG-Data-File
ONEPKG-Microsoft-OneNote-package-file
ONE-SEMONE-Compressed-Archive
ONE-SEMONE-Compressed-Archive-file
ONETMP-Microsoft-OneNote-temporary-file
ONF-Open-Navigation-Format-File
ON-Midiprg-Steinberg-Cubasis-Fonts-compressed-file
ONPF-Apple-DocViewer-Prefs
ON-Steinberg-Cubase-fonts-compressed-file
ON-Tuningwrench-Audio-Utility-compressed-file
ONW-Omron-HMI-NTST-file
OO1-Voice-file-Typhoon
O-Object-file-Atari
O-Object-file-GCC
O-Object-file-Unix
OOF-Data-Outrage-3D-Object-Format-Descent
OO-Free-Pascal-Object-File-for-OS-2-Version-FPC-Development-Team
OOGL-Object-Oriented-Graphics-Library
OOM-Swap-file-Shroom
OOP-OOP-compressed-archive-Header
OOP-OOP-Packer-archive-file
OOS-OpenOffice-org-spreadsheet-file
O-Outfile-Sprint
O-Output-File
OP2-Musplay-1-72-file
OP2-NEi-Nastran-Binary-Results-Neutral-File
OP2-Outpost-2-Saved-Game
OP2-Stanford-Research-Systems-Optimlelt-file
OPA-Psion-OPL-object-file
OPA-Psion-OPL-Object-File-Psion-PLC
OPC-Beta-44-Job-File
OPC-Office-Upgrade-Control-file-Header
OPC-Office-Upgrade-Control-File-Microsoft-Corporation
OPD-Durango-Interferometry-data-Header
OPD-Durango-Interferometry-Software-document-file
OPD-OmniPage-Document
OPD-ZX-Spectrum-emulator-file
OPENBSD-OpenBSD-Readme-File
TechTarget file types