The Unarchiver - Get the top application for archives on Mac. It's a RAR extractor, it allows you to unzip files, and works with dozens of other formats.

HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.

Engrampa - A file archiver for MATE, based on File Roller from GNOME 2 http://www.mate-desktop.org/

Dr.Explain - Dr.Explain software is a help file authoring tool.

ArKiwi - A lightweight and very fast file archiver, where you can add, compress, extract, delete, password protect, and blazing fast search all your files.

MadCap Flare - Documentation for Any Audience, Language or Format