I compiled (on Fatdog 810b) a slackbuild for "chmlib" which is a utility to access MS ITSS files.
chmlib-0.40-x86_64-1_SBo.tgz
**Modified to work with newer source
***Needs more verification
chmlib is a small library designed for accessing MS ITSS files.
The ITSS file format is used for Microsoft Html Help files (.chm),
which have been the predominant medium for software documentation
from Microsoft during the past several years, having superceded
the previously used .hlp file format.
https://slackbuilds.org/repository/12.0 ... es/chmlib/
I compiled this tool because it appeared to be missing when I was trying to build recoll.
https://slackbuilds.org/repository/14.1/desktop/recoll/
Recoll is a tool that let's you search your desktop for file content. I suspect this dependency is due to people running wine wanting to search the help files.