| ipkg | Indicore SDK Package |
| iplb | Apple iPhoto Library File |
| ipm | Image-Pro Plus Macro |
| ipmeta | Apple iPhoto Metadata |
| ipp | OmniPage Image Enhancement Template |
| ipr | TINA Interpreter File |
| ips | VisualBoy Advance IPS Patch File |
| ipspot | Apple iPhoto Spot File |
| iptc | IPTC Photo Metadata |
| iptheme | IconPackager Raw Theme Data |
| ipz | ICQ Plus skin |
| iqc | CADIQ Comparison Analysis Data |
| iqd | Cognos Impromptu Query Definition |
| iqe | Inter-Quake Export |
| iql | CADIQ Log |
| iqm | Inter-Quake Model |
| iqr | CADIQ View Analysis Results Data |
| iqs | CADIQ Summary Log |
| iqt | Tektronics RSA306 TIQ Data |
| iqx | Nexjen IQX Data |
| iraf | IRAF Data |
| irafhosts | IRAF Hosts Data |
| ird | 3K3Y IRD File |
| irl | HomeVision Infrared Signal Data |
| irl | AMX IR File |
| irn | IRedit Database |
| irock | intelliRock Sensor Data |
| irr | UVBrewer Irradiance File |
| irt | IRIT 3D Model |
| irt | Graphicon Interactive RealTime PHIGS |
