Helpfiles are basically html. Lots of things are not supported that you'd expect, but a helpfile you create in this format will be perfectly viewable from a web browser.
This could, of course, be texinfo'ed, but that is not particularly well documented (except by texinfo documents. Ick) and it looks like it's a very expensive (spacewise) operation.
Helpfile navigation: [tab] goes to next @link or @index
Special characters: < less than. > greater than. & ampersand. ! decimal 33.