The Org Manual: JavaScript support

Sebastian Rose has written a JavaScript program especially designed to enhance the web viewing experience of HTML files created with Org. This program allows you to view large files in two different ways. The first one is an Info-like mode where each section is displayed separately and navigation can be done with the n and p keys (and some other keys as well, press ? for an overview of the available keys). The second view type is a folding view much like Org provides inside Emacs. The script is available at http://orgmode.org/org-info.js and you can find the documentation for it at http://orgmode.org/worg/code/org-info-js/. We host the script at our site, but if you use it a lot, you might not want to be dependent on http://orgmode.org and prefer to install a local copy on your own web server.

#+INFOJS_OPT: view:info toc:nil

If this line is found, the HTML header will automatically contain the code needed to invoke the script. Using the line above, you can set the following viewing options:

path:    The path to the script.  The default is to grab the script from
         http://orgmode.org/org-info.js, but you might want to have
         a local copy and use a path like ‘../scripts/org-info.js’.
view:    Initial view when the website is first shown.  Possible values are:
         info      Info-like interface with one section per page.
         overview  Folding interface, initially showing only top-level.
         content   Folding interface, starting with all headlines visible.
         showall   Folding interface, all headlines and text visible.
sdepth:  Maximum headline level that will still become an independent
         section for info and folding modes.  The default is taken from
         org-export-headline-levels (= the H switch in #+OPTIONS).
         If this is smaller than in org-export-headline-levels, each
         info/folding section can still contain child headlines.
toc:     Should the table of contents initially be visible?
         Even when nil, you can always get to the "toc" with i.
tdepth:  The depth of the table of contents.  The defaults are taken from
         the variables org-export-headline-levels and org-export-with-toc.
ftoc:    Does the CSS of the page specify a fixed position for the "toc"?
         If yes, the toc will never be displayed as a section.
ltoc:    Should there be short contents (children) in each section?
         Make this above if the section should be above initial text.
mouse:   Headings are highlighted when the mouse is over them.  Should be
         ‘underline’ (default) or a background color like ‘#cccccc’.
buttons: Should view-toggle buttons be everywhere?  When nil (the
         default), only one such button will be present.

You can choose default values for these options by customizing the variable org-html-infojs-options. If you always want to apply the script to your pages, configure the variable org-html-use-infojs.

12.6.11 JavaScript supported display of web pages