ChmFox is described as 'Mozilla Firefox extension which brings the best CHM file reading experience to all platforms. CHM file could be viewed directly in Firefox using this extension under Windows, Mac and Linux'. There are six alternatives to ChmFox for Windows, Linux, Mac, BSD and PortableApps.com. The best alternative is xchm, which is both free and Open Source. Other great apps like ChmFox are Kchmviewer (Free, Open Source), Microsoft HTML Help (Free), CHM Decoder (Free) and CHMPane (Free, Open Source).
Kchmviewer is a free, open-source CHM (MS HTML help) and EPUB viewer written in C++ for Unix, Mac and Windows systems. Unlike most existing CHM viewers for Unix, it uses Trolltech Qt widget library, and could optionally be compiled for better KDE integration.
Microsoft HTML Help is the standard help system for the Windows platform. Authors can use HTML Help to create online help for a software application or to create content for a multimedia title or Web site.
CHM Decoder may decompile your CHM file (Compiled Windows HTML Help) or e-book and extract all source files. This tool free for use and work easily and quickly. Want to convert CHM to HTML and view that in your PocketPC or in your web pages? CHM Decoder can help to you.