Microsoft Compiled HTML Help

Microsoft Compiled HTML Help
Filename extension
.chm
Internet media type
application/vnd.ms-htmlhelp
Developed byMicrosoft
Initial release1997
Latest release
1.4
Extended to.lit
Microsoft HTML Help Executable
Other nameshh.exe
Developer(s)Microsoft
Included withMicrosoft Windows
PredecessorMicrosoft WinHelp
SuccessorMicrosoft Help 2
TypeHelp 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.