| hob | CARIS Hydrographic Object Binary Data |
| hobj | HALCON v12 Iconic Object |
| hobo | Onset HOBO Data Logger Data |
| hoe | Subaru HDS++ OPE File Editor Data |
| hof | WaterGEMS Transient Results Viewer Data |
| hol | Microsoft Outlook Holiday Data |
| hola | Human-like Orthogonal Layout Algorithm Data |
| hom | PLINK Homozygosity Data |
| homog | PLINK Homogeneity Test Report Data |
| hor | Heliosoft AttriGenPlus Input Horizon File |
| hot | WRAP HYD Output Data |
| hotlist | Internet Explorer Hotlist Data |
| hpb | IRAM Plateau de Bure Interferometer Header |
| hpdata | Heat Pump Design Model Data |
| hph | Designer Graphics System 2 Data |
| hpid | HP Instant Delivery Software Data |
| hpkg | Halotea Media Package |
| hpm | HAHTsite Runtime Project Map |
| hpr | Adobe RoboHelp Internal Data |
| hprof | Java Hprof Data |
| hps | HP Digital Sender Information |
| hpx | MetaVR 3D Model |
| hpz | Helpinator Zipped Archive |
| hqf | QuiltCAD Stitch Data |
| hqp | CP/M Disk Utility Data |
| hqx | Macintosh BinHex Encoded File |
| hr2 | Poser Hair Data |
| hr5 | Heredis 2000 Family History Data |
| hrb | TIBCO Hawk Rulebase Data |
| hrc | AQUA Hydrogen Bond Distance Restraints Counts Data |
| hrc | Softimage 3D Model |
| hrd | MSC Patran Device-dependent Hardcopy Output File |
| hrf | HyperRipper Data |
| hrm | Netmino HRM Data |
| hrm | Polar Heart Rate Monitor Data |
