Microsoft's HTML Help Workshop and Compiler generate CHM files by instructions stored in a HTML Help project. The hh.exe utility on Windows and the extract_chmLib utility (a component of chmlib) on Linux can also decompile CHM files. Various applications, such as HTML Help Workshop and 7-Zip can decompile CHM files. Sumatra PDF supports viewing CHM documents since version 1.9. CHM files are sometimes used for e-books. lit file format is a modification of the HTML Help CHM format.

Extended character support, although it does not fully support Unicode.ĬHM files support the following features: The file starts with bytes 'ITSF' (in ASCII), for 'Info-Tech Storage Format', which is the internal name given by Microsoft to the generic storage file format used in with CHM files. The file format has been reverse-engineered and documentation of it is freely available. It contains a set of HTML files, a hyperlinked table of contents, and an index file. Help is delivered as a binary file with the. Microsoft has announced that they do not intend to add any new features to HTML Help. Microsoft decides not to release Microsoft Help 2 as a general Help platform. HTML Help 1.33 releases with Internet Explorer 6 and Windows XP.Īt the WritersUA (formerly WinWriters) conference, Microsoft announces plans for a new help platform, Help 2, which is also HTML based. HTML Help 1.32 releases with Internet Explorer 5.5 and Windows Me. HTML Help 1.0 (HH 1.0) is released with Internet Explorer 4. Microsoft announces plans to stop development of WinHelp and start development on HTML Help. Although the format was designed by Microsoft, it has been successfully reverse-engineered and is now supported in many document viewer applications. Within the Windows NT family, the CHM file support is introduced in Windows NT 4.0 and is still supported in Windows 11. It was introduced as the successor to Microsoft WinHelp with the release of Windows 95 OSR 2.5 and consequently, Windows 98. The format is often used for software documentation.

The files are compressed and deployed in a binary format with the extension.

Microsoft Compiled HTML Help is a Microsoft proprietary online help format, consisting of a collection of HTML pages, an index and other navigation tools. Microsoft Compiled HTML Help Developer(s)

Open chm file