I've started a simple CHM viewer based on QWebEngine. https://tsdgeos.blogspot.com/2020/05/chmk-simple-chm-viewer.html
If we get it to a usable state (it's almost there, needs a bit more UI, but shouldn't be that hard to do) I think we can drop CHM support in Okular thus getting rid of KHTML that will most probably never make it to Qt6. Merge Requests welcome :) Cheers, Albert
