| handlebars | Handlebars Template |
| has | Haskell Script |
| hash | Crestron SIMPL Autoupdate Hash Data |
| haxe | Haxe Source Code |
| hbb | HAHTsite HAHTtalk Basic Object Data |
| hbs | HAHTsite HAHTtalk Basic Code Page |
| hbs | Handlebars Template |
| hbw | HAHTsite Widget Source Code |
| hcf | Compact HAM Library |
| hdcl | Hierarchical Dynamic Composition Language Document |
| hdev | HDevelop Data |
| hdmp | Windows Heap Dump |
| hdvp | HDevelop External Procedure |
| hdx | Delphi MultiHelp Index |
| hei | Heitml Source Code |
| hen | HEN Project |
| het | WinSQL HTML Export Template |
| hex | Intel HEX Format Data |
| hg | GNOME C++ Header |
| hg | Mercurial Data |
| hgdeps | Mercurial Dependencies Data |
| hgignore | Mercurial Ignore Data |
| hgsigs | Mercurial Signatures Data |
| hgsub | Mercurial Subrepo Data |
| hgtags | Mercurial Tags Data |
| hh | C++ Header File |
| hh | HTML Help Header File |
| hhc | HTML Help Table of Contents |
| hhh | Power C Precompiled Header |
| hhk | HTML Help Index |
| hhl | Visual Basic Data |
| hi | Haskell Interface |
| hic | HicEst Script |
| hie | GHC HI Extended |
| hint | Visual C++ Hint Data |
