Reference > Help Formats

HTML Help is now fully established as the standard Windows help format and unless you have a very good reason to use something else it is the best choice for online help distributed with modern Windows applications. Users are familiar with it, navigation is intuitive, it looks modern and attractive and it supports all the interactive and context-sensitive help technologies that make good help effective. And since it is HTML-based you have enormous flexibility for both formatting and introducing special features and functions.

HTML Help does have a couple of small disadvantages but they are definitely outweighed by the benefits. It is not ideal for web-based help or for help on networks, but it is the top choice for help installed with applications on the user's computer.

Windows XP restrictions on HTML Help on network drives:

Recent security updates to Windows XP have introduced some restrictions for accessing HTML Help files across network drives. Under Windows XP most file links in HTML Help files will now generally not work at all across networks and HTML Help itself is also restricted. Without registry changes on the user's computer HTML Help now cannot be used at all on network drives. More details and a fix for this problem are available on the Help & Manual user forum.

Features and pros and cons of HTML Help:

File extension:	.CHM
Format:	One .CHM file contains the entire help.
Platforms:	Windows 32 bit, viewer is pre-installed in Windows 98 and later
Typical use:	Local online help for applications installed on the user's local computer
Table of contents:	Yes. Integrated in the .CHM file and always visible in the viewer. Excellent, immediately intuitive navigation for the user.
Keyword index:	Yes
Full text search:	Yes
Context sensitive help:	Yes, full context-sensitive help support
Popups:	Yes, both in the help viewer and for context-sensitive help. Natively, HTML Help supports text-only popups without formatting or graphics. Help & Manual can also produce dual-mode HTML Help, in which the popups are output to a classic Winhelp .HLP file supporting formatted text and graphics but no hyperlinks. In addition to this you can also use Help & Manual's new JavaScript popups in HTML Help. In addition to formatted text and graphics JavaScript popups also support hyperlinks and even videos and animations.
Multimedia:	Flash animations and all supported video formats are supported. However, support for playing the formats used must also be installed on the user's computer. For example, if you use a DiVX video don't expect it to be playable on all user machines!
Printable by user:	The Print function of HTML Help is very limited. The help viewer can print topics and chapters but each topic is printed on a separate page.
Pros:	Single file containing all topics, graphics and the table of contents. More attractive, modern appearance than classic Winhelp. Intuitive, directory tree style table of contents that is always visible to the user. Flexible formatting with HTML (in Help & Manual you have full control over your topic pages with HTML templates), including the ability to add functions with JavaScript etc. by adding your own code to topics and templates.The HTML base makes it easy to produce a browser-based version for the web that looks almost identical to the HTML Help version.
Cons:	Popup topics are limited to plain text in native mode but this restriction can be solved in Help & Manual with dual-mode help.The HTML Help viewer is not pre-installed on the original versions of Windows 95 and NT4 but most users of these systems have now updated and this issue is becoming less and less relevant. You may want to deploy the redistributable HTML Help update package from Microsoft for the tiny minority of users who do not have it installed. The Viewer is based on a subset of MS Internet Explorer, which must be installed on the user's computer for HTML Help to be available. Problems with deployment on networks, only really suitable for local help.