Microsoft Compiled HTML Help
| Filename extension | 
.chm | 
|---|---|
| Internet media type | 
application/vnd.ms-htmlhelp | 
| Developed by | Microsoft | 
| Initial release | 1997 | 
| Latest release | 1.4  | 
| Extended to | .lit | 
| Microsoft HTML Help Executable | |
|---|---|
| Other names | hh.exe | 
| Developer(s) | Microsoft | 
| Included with | Microsoft Windows | 
| Predecessor | Microsoft WinHelp | 
| Successor | Microsoft Help 2 | 
| Type | Help system | 
Microsoft Compiled HTML Help (CHM) is a Microsoft proprietary online help format, consisting of a collection of HTML pages, an index and other navigation tools. The files are compressed and deployed in a binary format with the extension .CHM. The format was intended to succeed Microsoft WinHelp.
Although the format was designed by Microsoft, it has been successfully reverse-engineered and is now supported by many document viewers.