Someone asked me the following question:

I'm considering using a wiki as a documentation tool for a collaboratively written project. The main functionally I need is a table-of-contents navigation, probably similar to how a document tree or outline format nests links under a multiple categories.

In response, I wrote up the following review of some of the Wiki and CMS options I've used and am familiar with. This isn't an exhaustive survey of the solutions out there, but my report of solutions I have experience using feel confident recommending. Other suggestions are welcome.

TOC of Single Page

When I left Bell Labs, we were using Twiki and were using the built in TOC variable for pages. Like Word Processing table of contents, this works by editing your page naturally using headings, and then inserting a %TOC% variable at the top of the page. The variable automatically generates a table of contents based on the headings you've used in the page. MediaWiki features a similar TOC variable.

Twiki TOC

MediaWiki TOC

TOC of Multiple Chapters and Pages

If you're looking to create a document that consists of a series of chapters and pages, like a traditional book, then you might be more interested in Drupal's Collaborative Book module. This module allows you to create books with chapters, and assign pages to chapters in the book. You work organically by creating pages and assigning the pages in a hierarchical book outline. The Drupal documentation itself is built as a series of books.

The administrative display for organizing a book is really quite good.

I was working with a client that wanted to basically take a printed publication and later move their editing process to a web-based application that allowed them to provde a companion ebook. The idea of a living document suited itself to using Drupal's book module. With the module, they can create a site organized in chapters as the printed book is, and also export or print the book as a single page PDF.