Software documentation often needs to support users in different situations. A user working inside a Windows program may want an answer without leaving the application. Someone considering the program before installation may want to read the documentation online. A user working from a phone may also need access to the same information through a web browser. These situations can be supported with a CHM file bundled with the application and online help published on a website. With help authoring tool software, teams can produce both from one project, allowing the documentation to be written once and maintained in one place.
What CHM Files Are Good For
CHM stands for Microsoft Compiled HTML Help. Microsoft introduced the format in 1997 as a successor to the older WinHelp system. It remains an option for delivering help with Windows desktop applications.
One File That Works Offline
A CHM file puts the help pages, table of contents, index, and search in one file. Windows can open the file with its HTML Help viewer. The user does not need a browser or an internet connection to read it. If the CHM file is shipped with the application, the help is available even when the user is offline.
Context-Sensitive Help Inside the Application
CHM files can also provide context-sensitive help. Each help topic can have an ID that the application uses to open that topic. For example, the program can use F1 to open the help topic for the current window. The user goes straight to the relevant instructions instead of looking for the topic in the manual.
What Online Help Adds Beyond CHM
Read It on Any Device Before Installing
Online help opens in a browser on a phone or desktop without requiring an installation. People can also find online documentation before they install the application. A CHM file does not provide that same access because it is normally distributed with the installed application.
One Version for Everyone
Online help can be updated directly on the website. When a page is corrected, users see the updated version without downloading a new help file. This makes it easier to keep the documentation current between product releases.
Create Online Help and CHM Files Together
Maintaining a Windows help file and a separate web manual means updating the same information in two places. Over time, the two versions can fall out of sync. Dr.Explain can export the documentation as HTML for online help and CHM for a bundled Windows help file. The same content, screenshots, and topic structure can be used in both formats.
Dr.Explain also lets you assign Help IDs to topics. A Windows application can use those IDs to open the relevant CHM topic when the user presses F1. This gives desktop users direct access to the instructions for the window they are using.
Two Formats, One Documentation Set
A CHM file gives Windows users access to help without an internet connection and can open the right topic from within the application. Online help makes the same information available through a browser. Teams do not need to maintain separate documentation for each format. Help authoring tool software such as Dr.Explain can produce both from the same project, making it possible to update the content in one place and use it in both formats.
