Important announcement: appledoc contributors needed
appledoc is command line tool that helps Objective-C developers generate Apple-like source code documentation from specially formatted source code comments. It's designed to take as readable source code comments as possible for the input and use comments as well as surrounding source code to generate visually appealing documentation in the form of HTML as well as fully indexed and browsable Xcode documentation set. Although there are several tools that can create HTML documentation for Objective-C, all of those know to me fall short in meeting the minimum of goals described in readme file.
appledoc is open source. It's licensed with modified BSD license. In plain language: you're allowed to do whatever you wish with the code, modify, redistribute, embed in your products (free or commercial), but you must include copyright, terms of usage and disclaimer as stated in the license, the same way as any other BSD licensed code.
Additionally you can of course use documentation generated by appledoc for your products (free or commercial), but you must attribute appledoc either in documentation itself or other appropriate place such as your website.
If for whatever reason you cannot agree to these terms, contact us through contact form on contact page, we'll do our best to help you out and find a workable solution!
Read the whole license at the bottom of appledoc readme file.