| .otm |
Outlook Macro File |
| .osc |
OpenStreetMap Change File |
| .opj |
Origin Project |
| .ont |
theWord Bible Text Module |
| .ot |
theWord Old Testament Text Module |
| .odl |
Object Description Language File |
| .ovh |
OMSI Vehicle Configuration File |
| .ocr |
Subtitle Workshop OCR Script |
| .os |
ObjectScript Source File |
| .opax |
Microsoft Office User Settings File |
| .opts |
Linux Configuration Options File |
| .osu |
Osu! Script |
| .opal |
Microsoft Office User Settings File |
| .op |
OpenPAT Report |
| .oll |
TrialDirector Object Load List |
| .opeico |
Opeico Text File |
| .ogs |
Origin LabTalk Script File |
| .odo |
Online Operating System Write Document |
| .od |
Mascopt Graph Request File |
| .ook |
Arachne Batch Script |
| .pct |
Picture File |
| .pl |
Perl Script |
| .php |
PHP Source Code File |
| .py |
Python Script |