I found a neat little program on MSDN that allows you to compile and decompile .chm files.
.chm files are just the basic Windows help files and are made up of HTML pages and images compiled into one unit. My motivation for finding the program was to decompile a C++ tutorial from .chm format to every HTML and image file that made it up. I wanted to recode the pages and add links to make the tutorial more usable, and with this tool, I was able to.
It's called HTML Help Workshop and is available at: