For versions of Delphi prior to, and including, Delphi 5, please download the following sample applications:
For Delphi versions 6 and 7 please download the following example which includes a Fast-Help Project:
For Delphi XE, you do not need to supply any of your own HtmlHelp.pas files. XE supplies it's own unit called HTMLHelpViewer. Add this to your applications "uses" list and your good to go.