Compiled HTML help (CHM help)
Microsoft compiled HTML help (also known as CHM help) is one of the most popular help formats for Windows-based software applications.
CHM help usually has a tri-pane that shows Contents, Index and Search tabs. These are usually on the left of the help window. It's possible to include other tabs, such as a Glossary.
To help different types of user, it is possible to include 'browse sequences' that allow people to navigate easily through topics that are relevant to their problems. For example, in accounting software, the CHM help might contain a browse sequence for 'year-end procedures'.
Compiled HTML help is a proprietary help format that runs only under Windows. If you need cross-platform support, use WebHelp, FlashHelp or pure HTML help. For more information, see the comparison of online help formats (www.techscribe.co.uk/techw/help_comparison.htm).