| .nbt |
Minecraft Named Binary Tag File, Nero BackItUp Template File |
| .nvi |
NVIDIA Driver File |
| .nts |
Lotus Notes Traveler Server Config File |
| .opml |
Outline Processor Markup Language File |
| .oeaccount |
Windows Mail Account File |
| .obi |
Outlook RSS Subscription File |
| .osm |
OpenStreetMap Map File |
| .osdx |
Search Connector Description File |
| .odg |
OpenDocument Graphic File |
| .opf |
FlipAlbum File |
| .officeui |
Microsoft Office UI Customization File |
| .orx |
RadiantOne VDS Database Schema |
| .owm |
OutWit XML Mashup File |
| .orderedtest |
Visual Studio Ordered Test File |
| .oxygene |
Oxygene Project File |
| .options |
SE-SOFT Configuration File |
| .ois |
Origin Analyses Theme File |
| .ofp |
Origin Function Plot Theme File |
| .pds |
PowerDirector Script File |
| .prx |
PSP Plugin File |
| .pln |
ArchiCAD Project File |
| .pvm |
Parallels Virtual Machine |
| .pdx |
Adobe Acrobat Index File |
| .pcast |
iTunes Podcast File |