The format was designed by Microsoft. CHM is really known as Microsoft Compiled HTML Help. The .chm files are ‘help’ files, consisting of HTML pages that include an index, images and a table of contents with hyperlinks to all pages.
It was introduced as the successor to Microsoft WinHelp with the release of Windows 98 and is still supported in Windows 7. Although this format was introduced by Microsoft, it’s now supported in many document viewer applications.
CHM and Technical Writing
CHM is the format that’s mostly used for software documentation. This is the area where the format really shines. For example, you work remotely and there is no internet connection but you need a user manual, so you can just download CHM and continue working. Here is another example, you migrate from a help authoring tool, and you need to import your documentation to another one. A great format for this situation is CHM because your TOC, hyperlinks and other doc structure elements will be imported successfully.
As this format is offline, how can you keep updated? Well, here I describe how I can do it using an online documentation tool but if you use something else, please, share your experience in the comments section, so we’ll gather more information here for technical writers.
So, here is what you can do for you .chm documentation. For example, ClickHelp (a software documentation tool that I use) has an Export wizard, so I just update my documentation and then I export it as chm:
The export wizard will guide you through and help you export your documentation.
For my second example, when you migrate from a help authoring tool, the steps are also easy: you just export your documentation as CHM and then import it (if a chosen documentation tool supports it):
The export wizard will guide you through as well:
Then you just need to drag and drop your .chm file:
Proceed with the steps and that’s it!
So, for creating CHM you can just use your technical writing tool. Otherwise, you can use tools that were created for this reason, for example, HTML Help Workshop and Documentation by Microsoft.
What tools do you use for creating CHM files?