chmsee
A Gtk+2 CHM document viewer
It uses chmlib to extract files. It uses gecko to display pages. It supports displaying multilingual pages due to gecko. It features bookmarks and tabs. The tabs could be used to jump inside the chm file conveniently. Its UI is clean and handy, also is well localized. It is actively developed and maintained. The author of chmsee is Jungle Ji and several other great people.
There is no official package available for openSUSE Leap 15.5Distributions
Unsupported distributions
The following distributions are not officially supported. Use these packages at your own risk.