| idv | Autodesk Inventor Design View |
| idw | Autodesk Inventor Drawing |
| ifcxml | Industry Foundation Classes XML |
| ifd | InForm Document |
| ife | InfoFind Encrypted Document |
| ig2 | Catia IGES Document |
| igds | Bentley MicroStation Design |
| iges | IGES Drawing |
| igf | Intercept Geometry File |
| igj | iGrafx Published Web Content |
| igr | SmartSketch Drawing |
| igs | IGES Drawing |
| igt | iGrafx Document Template |
| igx | iGrafx Document |
| ihf | IGOR Pro Help File |
| ihf | Inspiration Handheld Document |
| iif | Intuit QuickBooks Interchange File |
| ijpds | Scitex IJPDS File |
| ila | DATEV Document |
| ildoc | Interleaf Document |
| ilg | InstallShield Log |
| imm | iMindmap 4 Document |
| imp | Impatica Classic Document |
| imr | Impromptu Report File |
| imtx | iMindMap Template File |
| imx | iMindMap 5 Exported Document |
| inca | Adobe InCopy CS3 Assignment File |
| incd | Adobe InCopy 2.0 Document |
| inct | Adobe InCopy CS3 Template |
| incx | Adobe InCopy Interchange Document |
| indb | Adobe InDesign Book |
| indl | Adobe InDesign Library |
| indt | Adobe InDesign Template |
| info | GNU Info Document |
| infopathxml | Microsoft InfoPath XML Form |
