| .HDP | Microsoft Corporation | File con immagini raster | HD Photo File | Adobe Photoshop | Adobe Systems Incorporated |
| .HDT | Adobe Systems Incorporated | File di settaggi | Photoshop HDR Toning Preset File | Adobe Photoshop CC | Adobe Systems Incorporated |
| .HELPCFG | Adobe Systems Incorporated | File di settaggi | Adobe AIR Help Configuration | Adobe AIR | Adobe Systems Incorporated |
| .HLM | Adobe Systems Incorporated | File di testo | Winhelp Vbhilfe File | Adobe Authorware | Adobe Systems Incorporated |
| .HLP | Microsoft Corporation | File di sistema | Windows Help File | Adobe RoboHelp | Adobe Systems Incorporated |
| .HPJ | Microsoft Corporation | File di sistema | Help Project File | Adobe RoboHelp | Adobe Systems Incorporated |
| .HPR | Adobe Systems Incorporated | File di settaggi | Internal RoboHelp File | Adobe RoboHelp | Adobe Systems Incorporated |
| .HSE | Adobe Systems Incorporated | File sviluppatore | Homesite Snippet End | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTA | Microsoft Corporation | File eseguibili | HTML Application | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTACCESS | Apache Software Foundation | File web | Apache HTACCESS File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTM | Various Developers | File web | Hypertext Markup Language File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTML | Various Developers | File web | Hypertext Markup Language File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTML5 | Sublime HQ Pty Ltd | File sviluppatore | HTML5 Hypertext Markup Language Revision 5 Source Code | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HTMLS | Open Source | File web | HTML With Server-Side Include | Adobe Dreamweaver | Adobe Systems Incorporated |
| .HYP | Interscape | File compressi | HYPER Compressed Archive | Adobe Illustrator CC | Adobe Systems Incorporated |
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