Cross-platform help viewer with search functionality
wxHtmlHelpController doesn't support any scripting within pages, nor does it support css.
I am looking for a help viewer like Windows CHM that basically provides support for 

adding content in HTML format
define Table of Contents
decent search

It should work on Windows, Mac and Linux. Bonus points for also having support for generating a "plain HTML/javascript" version that can be viewed in any browser (albeit without search support).
Language preference: Python