| irf | WinPLOTR IRF Data |
| irl | AMX IR File |
| irl | HomeVision Infrared Signal Data |
| irn | IRedit Database |
| irock | intelliRock Sensor Data |
| irr | UVBrewer Irradiance File |
| irr | AquaCrop Irrigation Data |
| irr8 | Avantes Avasoft v8 Absolute Irradiance Mode Data |
| irs | LabControl Spectacle Binary Data |
| irt | IRIT 3D Model |
| irt | Graphicon Interactive RealTime PHIGS |
| irtp | Graphicon Interactive RealTime PHIGS |
| irx | Brewer Lamp Irradiance File |
| is1 | SmartWare Input-Screen File |
| is1 | Komori PCC Intermediate Ink Profile |
| is2 | SmartWare Input-Screen File |
| is3 | SmartWare Input-Screen File |
| is4 | SmartWare Input-Screen File |
| isale | iSale Auction Data |
| isaletemplate | iSale Auction Template Data |
| isallic | iSale License Data |
| isam | ISAM Database |
| iscf | Intel Schematic Connectivity Format Data |
| iscorrupt | Skype Corrupted Data |
| iscsi | Daemon Tools ISCSI Target Data |
| isd | Altair FEKO Calculated Field Distribution Data |
| isdb | iThink Database |
| isds | IRAC Science Data Simulator Output Data |
| ise | InstallShield Express File |
| iset | ARToolKit NFT Image Set |