| hdr | Mail.dat Header File |
| hdr | MicroSim PCBoard Hole-drill Schedule Report |
| hdr | Microsoft IIS NNTP Header Data |
| hdr | Procomm Plus Message Header |
| hdt | Snapform Designer Background Layer Data |
| hdu | FM-ONE User Data |
| hdumx | HotDocs User Mapping XML |
| hdz | Poser Compressed Hand Data |
| he2 | Hierarchical Data Format File |
| he4 | Hierarchical Data Format Release 4 Data |
| he5 | Hierarchical Data Format Release 5 |
| hea | PhysioBank Header File |
| hec | Pvquan Heckbert Data |
| hedata | HTML Executable Publication Data |
| hef | HEAT Export Data |
| heg | GRABLOX HEG Data |
| heinf | HippoEDIT File Information |
| hejs | HippoEDIT Javascript |
| hemcr | HippoEDIT Macro |
| heo | NASA Solve getpar Earth Orientation Data |
| hep | Hummingbird HostExplorer Profile |
| het | PLINK Method-of-moments F Coefficient Estimates Data |
| heu | Adobe Flash Player Cache Metadata |
| hevbs | HippoEDIT VB Script |
| hewsp | HippoEDIT Workspace |
| hex | BinHex Encoded Data |
| hexbook | HHD Hex Editor Bookmarks Data |
| hexhis | Hex Editor Neo History Data |
| hexlic | Hex Editor Neo License Data |
| hexpatch | Free Hex Editor Neo Patch |
| hexsel | Hex Editor Neo Selection Data |
| hf2 | L3DT Compressed Heightfield Data |
| hfe | Altair FEKO Magnetic Field Strengths Data |
| hff | L3DT Heightfield Data |
| hfg | HeroForge-Anew Character Data |
