| ipe | Microth InPad Stroke Set |
| ipf | F-Secure Incremental Policy File |
| ipf | IGOR Pro Procedure File |
| ipfix | Internet Protocol Flow Information Export Protocol Data |
| ipflib | DWOS Implant Library Data |
| iphoto | Apple iPhoto Photo Library |
| ipi | Microsoft Windows Installer Data |
| ipkg | Indicore SDK Package |
| ipl22 | PLATO Learning System Temporary Data |
| iplb | Apple iPhoto Library File |
| ipm | Image-Pro Plus Macro |
| ipmeta | Apple iPhoto Metadata |
| ipp | OmniPage Image Enhancement Template |
| ipr | TINA Interpreter File |
| iprep | KIVA-3 Input Data |
| ips | VisualBoy Advance IPS Patch File |
| ipsa | IPSA Scene Data |
| ipspot | Apple iPhoto Spot File |
| iptc | IPTC Photo Metadata |
| iptheme | IconPackager Raw Theme Data |
| ipz | ICQ Plus skin |
| iq4 | IQ4E Controller Strategy Data |
| iqc | CADIQ Comparison Analysis Data |
| iqd | Cognos Impromptu Query Definition |
| iqdat | Inquisit Data |
| iqe | Inter-Quake Export |
| iqf | Integra 3.0 Query Data |
| iql | CADIQ Log |
| iqm | Inter-Quake Model |
| iqr | CADIQ View Analysis Results Data |