There are many chmviewers.
kchmviewer (if kde is installed)
xchm
gnochm (if using gnome)
There are others. Yum may be able to install depending on your repos. I only get from the source and compile from there. So you can use google to search for the two as well as for others. I would google from here.
http://www.google.com/linux
Also used the search tool here and found some related post.
Brian
